COMMISSION IMPLEMENTING DECISION (EU) 2024/2974
of 29 November 2024
establishing the best available techniques (BAT) conclusions, under Directive 2010/75/EU of the European Parliament and of the Council on industrial emissions, for the smitheries and foundries industry
(notified under document C(2024) 8322)
(Text with EEA relevance)
Article 1
Article 2
ANNEX
1.
Best available techniques (BAT) conclusions for the smitheries and foundries industry
SCOPE
DEFINITIONS
General terms |
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Term used |
Definition |
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Casting |
A metal workpiece, produced using a casting process, which is ejected or released out of a mould. |
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Casting process |
Pouring molten metal into the cavity of a mould. The molten metal is subsequently allowed to solidify. |
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Centrifugal casting |
Molten metal is poured into a preheated rotating mould, placed either vertically or horizontally depending on the product shape. After pouring, the mould rotates around its central axis creating a centrifugal force which displaces the molten metal towards the periphery, forcing it to deposit on the walls of the mould. |
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Channelled emissions |
Emissions of pollutants into the environment through any kind of duct, pipe, stack, etc. |
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Clean scrap |
Scrap metal which meets at least all of the following characteristics:
Free means that residual impurities are present at such a low level that they do not adversely affect the environmental performance (e.g. increased TVOC, PCDD/F and/or heavy metal emissions) and the operation/safety of the plant. |
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Cold-setting processes |
Curing processes for moulds and cores where the sand binder hardens at ambient temperature. Curing begins immediately after the last component of the sand binder formulation is introduced in the mix. |
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Continuous casting |
Molten metal is poured into a water-cooled die that is open at the bottom or at the side. Through intensive cooling, the outside of the metal product solidifies while it is slowly pulled out of the mould. Subsequently, the product (e.g. bars, tubes, profiles) is cut to the desired product length. |
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Continuous measurement |
Measurement using an automated measuring system permanently installed on site. |
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Core-making |
Production of cores which can be solid or hollow. Cores are inserted into the mould to provide the internal cavities or part of the external shape of the casting before the mould halves are joined. |
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Diffuse emissions |
Non-channelled emissions to air. Diffuse emissions include both fugitive and non-fugitive emissions. |
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Direct discharge |
Discharge to a receiving water body without further downstream waste water treatment. |
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Dross |
Solid substances formed during the melting or holding of metal at the surface of the molten metal, e.g. by oxidation with air. |
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Existing plant |
A plant that is not a new plant. |
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Feedstock |
Any metal input in the smitheries production process. |
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Finishing |
In foundries, this includes a number of mechanical operations carried out after the casting process including deburring, abrasive cutting, chiselling, needling, fettling, slide grinding, shot blasting and welding. In smitheries, this includes fettling, deburring, machining, cutting and chipping. |
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Flue-gas |
The exhaust gas exiting a combustion unit. |
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Forging |
A deformation and metal-shaping process using heating and hammers (e.g. pneumatic, steam-driven, mechanical, electrical, hydraulic). |
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Full mould process |
Moulding technique using a foam pattern made of expanded polymers (e.g. expanded polystyrene) incorporated in chemically bonded sand. The foam pattern is lost upon pouring. This process is generally used for large castings. |
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Gas-hardening processes |
Curing processes for cores where a catalyst or hardener is injected in a gaseous form into the core box. |
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Gravity die-casting |
Molten metal is poured directly from a ladle into a die under gravity. After solidification, the die is opened and the metal workpiece is released. |
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Green sand |
Mixture of sand, clay (e.g. bentonite) and additives (e.g. coal dust, cereal binders) used for mould making. |
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Hazardous substances |
Hazardous substances as defined in point 18 of Article 3 of Directive 2010/75/EU. |
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Heat treatment |
A thermal process where castings (in foundries) or workpieces (in smitheries) are heated below their melting point to improve their physical properties. |
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High-pressure die-casting |
Molten metal is forced under pressure into a sealed mould cavity. It is held in place by a powerful compressive power until the metal solidifies. After solidification, the die is opened and the metal workpiece is released. |
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Hot-curing processes |
Curing processes for cores or moulds where the sand binder hardens into a heated core box or a heated pattern, both made of metal or wood. |
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Indirect discharge |
A discharge that is not a direct discharge. |
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Internal scrap |
Internal scrap consists of gates, risers, defective castings, and other metal pieces generated within the installation. |
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Ladle preheating |
Ladles used to transfer molten metal from a melting furnace to the casting process are preheated to a controlled temperature in order to dry the ladle after preparation, to minimise thermal shock and refractory wear during pouring and to reduce temperature losses of the molten metal. |
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Liquid metal output |
The amount of liquid metal produced in the melting furnaces. |
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Lost foam casting |
Foam patterns of the parts to be cast, made of expanded polymers (e.g. expanded polystyrene), are produced using automated moulding machines and assembled together into clusters. The clusters are subsequently incorporated in unbonded sand. Upon pouring, the molten metal causes the pyrolysis of the expanded polystyrene and fills the emptied space. |
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Low-pressure die-casting |
Molten metal is transferred from an airtight furnace through a riser tube into a metal die. The molten metal is pushed upwards into the die under low gas pressure. After solidification, the gas pressure is released allowing the still-molten metal in the riser tube to fall back into the furnace, the die is opened and the casting is released. |
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Major plant upgrade |
A major change in the design or technology of a plant with major adjustments or replacements of the process and/or abatement technique(s) and associated equipment. |
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Mass flow |
The mass of a given substance or parameter which is emitted over a defined period of time. |
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Metal melting |
The production of ferrous or non-ferrous molten metal using furnaces. This also includes melting of, for example, scrap generated on site and heat conservation of molten metal in holding furnaces. |
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Moulding |
Making of a mould into which the molten metal will be poured. This also includes the making of patterns. |
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Natural sand |
Mixture composed of silica sand (e.g. 85 %), clay (e.g. 15 %) and water. Generally, no other additives are added to the mixture. |
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New plant |
A plant first permitted at the site of the installation following the publication of these BAT conclusions or a complete replacement of a plant following the publication of these BAT conclusions. |
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Nodular iron |
Cast iron with carbon in a nodular/spheroidal shape, commonly referred to as ductile iron. |
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Nodularisation |
Treatment of molten cast iron with magnesium or with a rare-earth element to change the carbon particles into a nodular/spheroidal shape. |
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Periodic measurement |
Measurement at specified time intervals using manual or automated methods. |
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Heating/reheating |
A succession of thermal process steps used to raise the temperature of the feedstock before hammering. |
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Process chemicals |
Substances and/or mixtures as defined in Article 3 of Regulation (EC) No 1907/2006 and used in the process(es). Process chemicals may contain hazardous substances and/or substances of very high concern. |
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Refining of steel |
Steel treatment process to remove carbon (decarburisation) from pig iron (primary refining) followed by removal of impurities. |
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Residue |
Substance or object generated by the activities covered by the scope of these BAT conclusions as waste or by-product. |
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Sand reuse |
The process of reusing sand in a foundry after sand reconditioning or reclamation. |
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Sand reconditioning |
Any mechanical operation carried out at the installation to reuse green and/or natural sand. This includes screening, removing tramp metal, separating and removing fines and oversized agglomerates. The sand is then cooled and sent for storage/reuse. |
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Sand reclamation |
Any mechanical and/or thermal operation carried out at the installation to reuse chemically bonded sand or mixed sand. This includes an initial mechanical step (e.g. crushing, screening) followed by mechanical (e.g. grinding wheel, impact drum) and/or thermal (e.g. fluidised bed, rotary furnaces) processes in order to remove the residual binders. |
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Sensitive receptors |
Areas which need special protection, such as:
|
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Slag |
Liquid substances that do not dissolve in liquid metal but separate easily from them and form a separate layer on the liquid metal because of their lower density. Slag is formed by the oxidation of non-metallic elements that are present in the metal charge. |
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Substances of very high concern |
Substances meeting the criteria mentioned in Article 57 and included in the Candidate List of Substances of Very High Concern, according to the REACH Regulation ((EC) No 1907/2006(3)). |
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Surface run-off water |
Water from precipitation that flows over land or impervious surfaces, such as paved streets, storage areas and rooftops, and does not soak into the ground. |
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Treatment of molten metal |
Refining operations in aluminium melting processes which include degassing, grain refining, and fluxing. Degassing (i.e. removal of dissolved hydrogen using nitrogen) is often combined with cleaning (i.e. removal of alkali or alkaline earth metal such as Ca) using Cl2 gas. |
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Valid hourly (or half-hourly) average |
An hourly (or half-hourly) average is considered valid when there is no maintenance or malfunction of the automated measuring system. |
Pollutants and parameters |
|
Term used |
Definition |
Amines |
Collective term for derivatives of ammonia in which one or more of the hydrogen atoms has been replaced by an alkyl or aryl group. |
AOX |
Adsorbable organically bound halogens, expressed as Cl, include adsorbable organically bound chlorine, bromine and iodine. |
As |
The sum of arsenic and its compounds, dissolved or bound to particles, expressed as As. |
B[a]P |
Benzo[a]pyrene. |
BOD5 |
Biochemical oxygen demand. Amount of oxygen needed for the biochemical oxidation of organic and/or inorganic matter in 5 (BOD5) days. |
Cd |
The sum of cadmium and its compounds, dissolved or bound to particles, expressed as Cd. |
Cl2 |
Elemental chlorine. |
CO |
Carbon monoxide. |
COD |
Chemical oxygen demand. Amount of oxygen needed for the total chemical oxidation of the organic matter to carbon dioxide using dichromate. COD is an indicator for the mass concentration of organic compounds. |
Cr |
The sum of chromium and its compounds, dissolved or bound to particles, expressed as Cr. |
Cu |
The sum of copper and its compounds, dissolved or bound to particles, expressed as Cu. |
Dust |
Total particulate matter (in air). |
Fe |
The sum of iron and its compounds, dissolved or bound to particles, expressed as Fe. |
HCl |
Hydrogen chloride. |
HF |
Hydrogen fluoride. |
Hg |
The sum of mercury and its compounds, dissolved or bound to particles, expressed as Hg. |
HOI |
Hydrocarbon oil index. The sum of compounds extractable with a hydrocarbon solvent (including long-chain or branched aliphatic, alicyclic, aromatic or alkyl-substituted aromatic hydrocarbons). |
Mg |
Magnesium. |
MgO |
Magnesium oxide. |
MgS |
Magnesium sulphide. |
MgSO4 |
Magnesium sulphate. |
Ni |
The sum of nickel and its compounds, dissolved or bound to particles, expressed as Ni. |
NOX |
The sum of nitrogen monoxide (NO) and nitrogen dioxide (NO2), expressed as NO2. |
PCDD/F |
Polychlorinated dibenzo-p-dioxins/furans. |
Phenol index |
The sum of phenolic compounds, expressed as phenol concentration and measured according to EN ISO 14402. |
Pb |
The sum of lead and its compounds, dissolved or bound to particles, expressed as Pb (in water). The sum of lead and its compounds, expressed as Pb (in air). |
SO2 |
Sulphur dioxide. |
TOC |
Total organic carbon, expressed as C (in water), includes all organic compounds. |
TSS |
Total suspended solids. Mass concentration of all suspended solids (in water), measured via filtration through glass fibre filters and gravimetry. |
Total nitrogen (TN) |
Total nitrogen, expressed as N, includes free ammonia and ammonium nitrogen (NH4-N), nitrite nitrogen (NO2-N), nitrate nitrogen (NO3-N) and organically bound nitrogen. |
TVOC |
Total volatile organic carbon, expressed as C (in air). |
VOC |
Volatile organic compound as defined in Article 3(45) of Directive 2010/75/EU. |
Zn |
The sum of zinc and its compounds, dissolved or bound to particles, expressed as Zn. |
ACRONYMS
Acronym |
Definition |
CBC |
Cold blast cupola |
CMS |
Chemicals management system |
CMR |
Carcinogenic, mutagenic or toxic for reproduction. |
CMR 1A |
CMR substance of category 1A as defined in Regulation (EC) No 1272/2008 as amended, i.e. carrying the hazard statements H340, H350, H360. |
CMR 1B |
CMR substance of category 1B as defined in Regulation (EC) No 1272/2008 as amended, i.e. carrying the hazard statements H340, H350, H360. |
CMR 2 |
CMR 2 CMR substance of category 2 as defined in Regulation (EC) No 1272/2008 as amended, i.e. carrying the hazard statements H341, H351, H361. |
DMEA |
N,N-Dimethylethylamine |
EAF |
Electric arc furnace |
EMS |
Environmental management system |
ESP |
Electrostatic precipitator |
HBC |
Hot blast cupola |
HPDC |
High-pressure die-casting |
NFM |
Non-ferrous metal |
OME |
Operational material efficiency |
OTNOC |
Other than normal operating conditions |
TEA |
Triethylamine |
GENERAL CONSIDERATIONS
Best available techniques
Emission levels associated with the best available techniques (BAT-AELs) and indicative emission levels for emissions to air
Type of measurement |
Averaging period |
Definition |
Continuous |
Daily average |
Average over a period of 1 day based on valid hourly or half-hourly averages. |
Periodic |
Average over the sampling period |
Average value of three consecutive samplings/measurements of at least 30 minutes each(4). |
Emission levels associated with the best available techniques (BAT-AELs) for emissions to water
Other environmental performance levels associated with the best available techniques (BAT-AEPLs) and indicative levels
BAT-AEPLs for specific energy consumption (foundries)
Indicative levels for specific energy consumption (smitheries)
BAT-AEPLs for specific water consumption (foundries)
BAT-AEPLs for specific amount of waste sent for disposal (foundries)
Indicative levels for operational material efficiency (OME) (foundries)
BAT-AEPLs for sand reuse (foundries)
1.1.
General BAT conclusions
1.1.1.
Overall environmental performance
BAT 1.
In order to improve the overall environmental performance, BAT is to elaborate and implement an environmental management system (EMS) that incorporates all of the following features:
Note
Applicability
BAT 2.
In order to improve the overall environmental performance, BAT is to establish, maintain and regularly review (including when a significant change occurs) an inventory of inputs and outputs, as part of the EMS (see BAT 1), that incorporates all of the following features:
Applicability
BAT 3.
In order to improve the overall environmental performance, BAT is to elaborate and implement a chemicals management system (CMS), as part of the EMS (see BAT 1), that incorporates all of the following features:
Applicability
BAT 4.
In order to prevent or reduce emissions to soil and groundwater, BAT is to use all of the techniques given below.
Technique |
Description |
Applicability |
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a |
Set-up and implementation of a plan for the prevention and control of leaks and spillages |
A plan for the prevention and control of leaks and spillages is part of the EMS (see BAT 1) and includes, but is not limited to:
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The level of detail of the plan will generally be related to the nature, scale and complexity of the plant, as well as to the type and quantity of liquids used. |
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b |
Structuring and management of process areas and raw material storage areas |
This includes techniques such as:
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Generally applicable. |
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c |
Prevention of the contamination of surface run-off water |
Production areas and/or areas where process chemicals, residues or waste are stored or handled are protected against surface run-off water. This is achieved by using at least the following techniques:
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Generally applicable. |
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d |
Collection of potentially contaminated surface run-off water |
Surface run-off water from areas that are potentially contaminated is collected separately and only discharged after appropriate measures are taken, e.g. monitoring, treatment, reuse. |
Generally applicable. |
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e |
Safe handling and storage of process chemicals |
This includes the following:
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Generally applicable. |
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f |
Good housekeeping |
A set of measures aiming at preventing, or reducing, the generation of emissions (e.g. regular maintenance and cleaning of equipment, work surfaces, floors and transport routes, and containment as well as rapid clean-up of any spillages). |
Generally applicable. |
BAT 5.
In order to reduce the frequency of the occurrence of OTNOC and to reduce emissions during OTNOC, BAT is to set up and implement a risk-based OTNOC management plan as part of the EMS (see BAT 1) that includes all of the following elements:
Applicability
1.1.2.
Monitoring
BAT 6.
BAT is to monitor at least once every year:
Description
1.1.3.
Energy efficiency
BAT 7.
In order to increase the overall energy efficiency of the plant, BAT is to use all of the techniques given below.
Technique |
Description |
Applicability |
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Management techniques |
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a. |
Energy efficiency plan and audits |
An energy efficiency plan is part of the EMS (see BAT 1) and entails defining and monitoring the specific energy consumption of the activity/processes (e.g. kWh/t liquid metal), setting objectives in terms of energy efficiency and implementing actions to achieve these objectives. Audits (also part of the EMS, see BAT 1) are carried out at least once every year to ensure that the objectives of the energy efficiency plan are met and the audits recommendations are followed up and implemented. The energy efficiency plan may be integrated in the overall energy efficiency plan of a larger installation (e.g. surface treatment activities). |
The level of detail of the energy efficiency plan, of the audits and of the balance record will generally be related to the nature, scale and complexity of the plant and the types of energy sources used. |
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b. |
Energy balance record |
Drawing up an energy balance record once every year which provides a breakdown of the energy consumption and generation (including energy export) by the type of energy source, for example:
This includes:
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Process and equipment selection and optimisation |
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c. |
Use of general energy-saving techniques |
This includes techniques such as:
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Generally applicable. |
1.1.4.
Noise and vibrations
BAT 8.
In order to prevent or, where that is not practicable, to reduce emissions of noise and vibrations, BAT is to set up, implement and regularly review a noise and/or vibration management plan, as part of the EMS (see BAT 1), that includes all of the following elements:
Applicability
BAT 9.
In order to prevent or, where that is not practicable, to reduce noise emissions, BAT is to use one or a combination of the techniques given below.
Technique |
Description |
Applicability |
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a. |
Appropriate location of equipment and buildings |
Increasing the distance between the emitter and the receiver, by using buildings as noise screens and by relocating equipment and/or building openings. |
For existing plants, the relocation of equipment and openings of the buildings may not be applicable due to a lack of space and/or excessive costs. |
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b. |
Operational measures |
These include at least the following:
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Generally applicable. |
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c. |
Low-noise equipment |
This includes direct drive motors; low-noise compressors, pumps and fans; low-noise transportation equipment. |
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d. |
Noise control equipment |
This includes techniques such as:
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Applicability to existing plants may be restricted by a lack of space. |
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e. |
Noise abatement |
Inserting obstacles between emitters and receivers (e.g. protection walls, embankments). |
Only applicable to existing plants, as the design of new plants should make this technique unnecessary. For existing plants, the insertion of obstacles may not be applicable due to a lack of space. |
1.1.5.
Residues
BAT 10.
In order to increase material efficiency and reduce the amount of waste sent for disposal, BAT is to set up, implement and regularly review a residues management plan.
Description
Applicability
1.2.
BAT conclusions for foundries
1.2.1.
General BAT conclusions for foundries
1.2.1.1.
Hazardous substances and substances of very high concern
BAT 11.
In order to prevent or reduce the use of hazardous substances and substances of very high concern in moulding and core-making with chemically bonded sand, BAT is to use alternative substances which are non- or less hazardous.
Description
1.2.1.2.
Monitoring of emissions
1.2.1.2.1.
Monitoring of emissions to air
BAT 12.
BAT is to monitor channelled emissions to air with at least the frequency given below, and in accordance with EN standards. If EN standards are not available, BAT is to use ISO, national or other international standards that ensure the provision of data of an equivalent scientific quality.
Substance/Parameter |
Process(es)/source(s) |
Foundry/furnace type |
Standard(s) |
Minimum monitoring frequency(5) |
Monitoring associated with |
|
Amines |
Moulding using lost moulds and core-making(6) |
All |
No EN standard available |
Once every year |
BAT 26 |
|
Benzene |
Moulding using lost moulds and core-making(7) |
All |
No EN standard available |
BAT 26 |
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Casting, cooling and shake-out using lost moulds including full mould process(7) |
BAT 27 |
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B[a]P |
Metal melting(8) |
Cast iron |
No EN standard available |
Once every year |
- |
|
Carbon monoxide (CO) |
Heat treatment(9) |
All |
EN 15058 |
Once every year |
BAT 24 |
|
Metal melting |
Cast iron: CBC, HBC and rotary furnaces |
BAT 38 |
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NFM(9) |
BAT 43 |
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Dust |
Heat treatment(8) |
All |
EN 13284-1(11) (12) |
Once every year |
BAT 24 |
|
Metal melting |
Once every year(10) |
BAT 38 BAT 40 BAT 43 |
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Nodularisation(13) |
Cast iron |
Once every year |
BAT 39 |
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Refining |
Steel |
BAT 41 |
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Moulding using lost moulds and core-making |
All |
BAT 26 |
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Casting, cooling and shake-out using lost moulds including full mould process |
All |
BAT 27 |
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Finishing |
All |
BAT 30 |
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Lost foam casting |
Cast iron and NFM |
BAT 28 |
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Casting in permanent moulds |
All |
BAT 29 |
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Sand reuse |
All |
BAT 31 |
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Formaldehyde(8) |
Moulding using lost moulds and core-making |
All |
EN standard under development |
Once every year |
BAT 26 |
|
Casting, cooling and shake-out using lost moulds including full mould process |
Once every year |
BAT 27 |
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Gaseous chlorides |
Metal melting |
Cast iron: CBC, HBC and rotary furnaces(8) |
EN 1911 |
Once every year |
BAT 38 |
|
Aluminium(8) |
BAT 43 |
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Gaseous fluorides |
Metal melting |
Cast iron: CBC, HBC and rotary furnaces(8) |
EN standard under development |
BAT 38 |
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Aluminium |
BAT 43 |
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Metals |
Cadmium and its compounds |
Casting, cooling and shake-out using lost moulds including full mould process(8) |
All |
EN 14385 |
Once every year |
- |
Metal melting |
All |
Once every year |
- |
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Finishing(8) |
All |
Once every year |
- |
|||
Chromium and its compounds |
Casting, cooling and shake-out using lost moulds including full mould process(8) |
All |
Once every year |
- |
||
Metal melting(8) |
All |
Once every year |
- |
|||
Finishing(8) |
All |
Once every year |
- |
|||
Nickel and its compounds |
Casting, cooling and shake-out using lost moulds including full mould process(8) |
All |
Once every year |
- |
||
Metal melting(8) |
All |
Once every year |
- |
|||
Finishing(8) |
All |
Once every year |
- |
|||
Lead and its compounds |
Casting, cooling and shake-out using lost moulds including full mould process(8) |
All |
Once every year |
- |
||
Metal melting |
Cast iron: CBC and HBC(8) |
Once every year |
BAT 38 |
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NFM(14) |
BAT 43 |
|||||
Casting in permanent moulds |
Lead |
Once every year |
BAT 29 |
|||
Finishing(8) |
All |
Once every year |
- |
|||
Zinc and its compounds |
Metal melting(8) |
All |
Once every year |
- |
||
Nitrogen oxides (NOX) |
Heat treatment(9) |
All |
EN 14792 |
Once every year |
BAT 24 |
|
Thermal sand regeneration, except for sand originating from the cold-box process(9) |
All |
BAT 31 |
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Thermal regeneration of sand originating from the cold-box process |
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Metal melting |
Cast iron: CBC, HBC and rotary furnaces |
BAT 38 |
||||
NFM(9) |
BAT 43 |
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PCDD/F |
Metal melting |
Cast iron: CBC, HBC and rotary furnaces |
EN 1948-1, EN 1948-2, EN 1948-3 |
BAT 38 |
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Cast iron: Induction(8) |
BAT 38 |
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Steel and NFM(8) |
BAT 40 BAT 43 |
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Phenol |
Moulding using lost moulds and core-making(15) |
All |
No EN standard available |
Once every year |
BAT 26 |
|
Casting, cooling and shake-out using lost moulds including full mould process(15) |
BAT 27 |
|||||
Sulphur dioxide (SO2) |
Thermal regeneration of sand in which sulphonic acid catalysts have been used |
All |
EN 14791 |
Once every year |
BAT 31 |
|
Metal melting |
Cast iron: CBC, HBC and rotary furnaces |
BAT 38 |
||||
NFM(9) (16) |
BAT 43 |
|||||
Total volatile organic carbon (TVOC) |
Moulding using lost moulds and core-making |
All |
EN 12619 |
BAT 26 |
||
Lost foam, casting |
BAT 28 |
|||||
Casting, cooling and shake-out using lost moulds including full mould process |
BAT 27 |
|||||
Sand reuse |
BAT 31 |
|||||
Metal melting |
Cast iron |
BAT 38 |
||||
Steel and NFM(8) |
|
- |
||||
Casting in permanent moulds(17) |
All(8) |
|
BAT 29 |
1.2.1.2.2.
Monitoring of emissions to water
BAT 13.
BAT is to monitor emissions to water with at least the frequency given below, and in accordance with EN standards. If EN standards are not available, BAT is to use ISO, national or other international standards that ensure the provision of data of an equivalent scientific quality.
Substance/parameter |
Process |
Standard(s) |
Minimum monitoring frequency(18) |
Monitoring associated with |
|
Adsorbable organically bound halogens (AOX)(19) |
Waste water from wet scrubbing of cupola off-gases |
EN ISO 9562 |
Once every 3 months(20) |
BAT 36 |
|
Biochemical oxygen demand (BOD5)(20) |
Die-casting, off-gas treatment (e.g. wet scrubbing), finishing, heat treatment, contaminated surface run-off water, direct cooling, wet sand regeneration and cupola furnace slag granulation. |
Various EN standards available (e.g. EN 1899-1, EN ISO 5815) |
|||
Chemical oxygen demand (COD)(20) (21) |
No EN standard available |
||||
Hydrocarbon oil index (HOI)(19) |
EN ISO 9377-2 |
||||
Metals/metalloids |
Arsenic (As)(19) |
Various EN standards available (e.g. EN ISO 11885, EN ISO 15586, EN ISO 17294-2) |
|||
Cadmium (Cd)(19) |
|||||
Chromium (Cr)(19) |
|||||
Copper (Cu)(19) |
|||||
Iron (Fe)(19) |
|||||
Lead (Pb)(19) |
|||||
Nickel (Ni)(19) |
|||||
Zinc (Zn)(19) |
|||||
Mercury (Hg)(19) |
Various EN standards available (e.g. EN ISO 12846, EN ISO 17852) |
||||
Phenol index(22) |
EN ISO 14402 |
||||
Total nitrogen (TN)(20) |
Various EN standards available (e.g. EN 12260, EN ISO 11905-1) |
||||
Total organic carbon (TOC)(20) (21) |
EN 1484 |
||||
Total suspended solids (TSS)(20) |
EN 872 |
1.2.1.3.
Energy efficiency
BAT 14.
In order to increase energy efficiency, BAT is to use all of the techniques (a) to (f), and an appropriate combination of the techniques (g) to (n) given below.
Technique |
Description |
Applicability |
|||||||||||||
Design and operation |
|||||||||||||||
a. |
Selection of an energy-efficient type of furnace |
See Section 1.4.1. |
Only applicable to new plants and/or major plant upgrades. |
||||||||||||
b. |
Techniques for maximising the thermal efficiency of furnaces |
See Section 1.4.1. |
Generally applicable. |
||||||||||||
c. |
Furnace automation and control |
See Section 1.4.1. |
Generally applicable. |
||||||||||||
d.. |
Use of clean scrap |
See Section 1.4.1. |
Generally applicable. |
||||||||||||
e. |
Improving casting yield and decreasing scrap generation |
See Section 1.4.1. |
Generally applicable. |
||||||||||||
f. |
Reducing energy losses/improving ladle preheating practices |
This includes all of the following elements:
|
Applicability may be restricted in the case of big ladles (e.g. > 2 t) and bottom pouring ladles due to design constraints. |
||||||||||||
g. |
Oxy-fuel combustion |
See Section 1.4.1. |
Applicability to existing plants may be restricted by furnace design and the need for a minimum waste gas flow. |
||||||||||||
h. |
Use of medium-frequency power in induction furnaces |
Use of medium-frequency (250 Hz) induction furnaces instead of mains frequency (50 Hz) furnaces. |
Generally applicable. |
||||||||||||
i. |
Compressed air system optimisation |
This includes all of the following measures:
|
Generally applicable. |
||||||||||||
j. |
Microwave drying of cores for water-based coatings |
Use of microwave drying ovens (e.g. with a frequency of 2 450 Hz) for drying cores coated with water-based coatings (see BAT 21 (e)), resulting in rapid and homogeneous drying of the entire core surface. |
May not be applicable to continuous casting processes or to the production of large castings, or when cores are made of reclaimed sand containing traces of carbon. |
||||||||||||
Heat recovery techniques |
|||||||||||||||
k. |
Scrap preheating using recovered heat |
Scrap is preheated by recovering the heat from hot flue-gases which are redirected to come into contact with the charge. |
Only applicable to shaft furnaces in non-ferrous metal foundries and to EAFs in steel foundries. |
||||||||||||
l. |
Heat recovery from off-gases generated in furnaces |
Waste heat from hot off-gases is recovered (e.g. through heat exchangers) and reused on site or off site (e.g. in thermal oil/hot water/heating circuits, for steam generation or for preheating of combustion air (see technique (m)). This may include the following:
|
Applicability may be restricted by the lack of a suitable heat demand. |
||||||||||||
m. |
Preheating of combustion air |
See Section 1.4.1. |
Generally applicable. |
||||||||||||
n. |
Waste heat utilisation in induction furnaces |
Waste heat from the induction furnace cooling system is recovered using heat exchangers for drying raw materials (e.g. scrap), space heating or hot water supply. |
Generally applicable. |
Process – Furnace type |
Unit |
BAT-AEPL (Yearly average) |
Melting and holding – Cold blast cupola |
kWh/t of liquid metal |
900 – 1 750 |
Melting and holding – Hot blast cupola |
900 – 1 500 |
|
Melting and holding – Induction |
600 – 1 200 |
|
Melting and holding – Rotary |
800 – 950 |
|
Ladle preheating |
50 – 150 (23) |
Process – Furnace type |
Unit |
BAT-AEPL (Yearly average) |
Melting – (EAF/induction) |
kWh/t of liquid metal |
600 – 1 200 |
Ladle preheating |
100 – 300 |
Process |
Unit |
BAT-AEPL (Yearly average) |
Melting and holding |
kWh/t of liquid metal |
600 – 2 000 |
1.2.1.4.
Material efficiency
1.2.1.4.1.
Storage and handling of residues, packaging and unused process chemicals
BAT 15.
In order to prevent or reduce the environmental risk associated with the storage and handling of residues, packaging and unused process chemicals and to facilitate their reuse and/or recycling, BAT is to use all of the techniques given below.
Technique |
Description |
|||||
a. |
Appropriate storage of various residue types |
This includes the following:
|
||||
b. |
Reuse of internal scrap |
Reuse of internal scrap directly or after treatment. The degree of reuse of internal scrap depends on its content of impurities. |
||||
c. |
Reuse/recycling of packaging |
Process chemicals packaging is selected to facilitate its complete emptying (e.g. considering the size of the packaging aperture or the nature of the packaging material). After emptying, the packaging is reused, returned to the supplier or sent for material recycling. Preferably, process chemicals are stored in large containers. |
||||
d. |
Return of unused process chemicals |
Unused process chemicals (i.e. which remain in their original containers) are returned to their suppliers. |
1.2.1.4.2.
Operational material efficiency in the casting process
BAT 16.
In order to increase material efficiency in the casting process, BAT is to use either technique (a) or technique (a) in combination with one or both of the techniques (b) and (c) given below.
Technique |
Description |
|
a. |
Improving casting yield and decreasing scrap generation |
See Section 1.4.2 |
b. |
Use of computer-aided simulation for casting, pouring and solidification |
A computer simulation system is used to optimise the casting, pouring and solidification process, to minimise the number of defective castings and increase foundry productivity. |
c. |
Production of light-weight castings using topology optimisation |
Use of topology optimisation (i.e. casting simulation by means of algorithms and computer programs) to reduce the product mass while meeting the product performance requirements. |
Foundry type |
Unit |
Indicative levels (Yearly average) |
Cast iron foundries |
% |
50 – 97 (24) (25) |
Steel foundries |
50 – 100 (24) (25) |
|
NFM foundries (all types except HPDC) – Pb |
50 – 97,5 (24) |
|
NFM foundries (all types except HPDC) – metals other than Pb |
50 – 98 (24) |
|
NFM foundries (HPDC) |
60 – 97 (24) |
1.2.1.4.3.
Reduction of material consumption
BAT 17.
In order to reduce material (e.g. chemicals, binders) consumption, BAT is to use an appropriate combination of the techniques given below.
Technique |
Description |
Applicability |
|||||||||||||
Techniques for aluminium high-pressure die-casting |
|||||||||||||||
a. |
Separate spraying of release agent and water |
See Section 1.4.2. |
Generally applicable. |
||||||||||||
b. |
Minimisation of release agent and water consumption |
Measures to minimise the consumption of release agent and water include:
|
Generally applicable. |
||||||||||||
Techniques for processes using chemically bonded sand and core-making |
|||||||||||||||
c. |
Optimisation of binder and resin consumption |
See Section 1.4.2. |
Generally applicable. |
||||||||||||
d. |
Minimisation of mould and core sand losses |
Production parameters of the various product types are stored in an electronic database that allows easy changeover to new products with minimised losses in time and materials. |
Generally applicable. |
||||||||||||
e. |
Use of best practices for cold-setting processes |
See Section 1.4.2. |
Generally applicable. |
||||||||||||
f. |
Recovery of amines from acid scrubbing water |
When acid washing is used (e.g. using sulphuric acid) to treat the cold-box off-gases, amine sulphate is formed. The amines are recovered from the treatment of amine sulphate using sodium hydroxide. This may take place on site or off site. |
Applicability may be restricted due to safety considerations (explosion hazard). |
||||||||||||
g. |
Use of best practices for gas-hardening processes |
See Section 1.4.2. |
Generally applicable. |
||||||||||||
h. |
Applying alternative moulding/core-making processes |
Alternative moulding/core-making processes using no or a reduced amount of binders include:
|
Applicability of the lost foam casting process to existing plants may be restricted due to the required infrastructure modifications. Applicability of vacuum moulding may be restricted in the case of large moulding boxes (e.g. above 1,5 m × 1,5 m). |
1.2.1.4.4.
Sand reuse
BAT 18.
In order to reduce the consumption of new sand and the generation of spent sand from sand reuse in the lost mould casting process, BAT is to use one or an appropriate combination of the techniques given below.
Technique |
Description |
Applicability |
|
a. |
Optimised reconditioning of green sand |
The green sand reconditioning process is controlled by a computer system to optimise raw material consumption and green sand reuse, e.g. cooling (evaporative or fluidised bed), addition of binders and additives, moistening, mixing, quality control. |
Generally applicable. |
b. |
Low-waste green sand reconditioning |
Green sand reconditioning in aluminium foundries is carried out using a scanner for identifying impurities in green sand based on brightness/colour. These impurities are separated from green sand using an air blast pulse. |
Generally applicable. |
c. |
Preparation of clay-bonded sand by vacuum mixing and cooling |
See BAT 25 (b). |
Generally applicable. |
d. |
Mechanical reclamation of cold-setting sand |
Mechanical techniques (e.g. breaking of lumps, segregation of sand fractions) using crushers or mills are used to reclaim cold-setting sand. |
May not be applicable to silicate-bonded sand. |
e. |
Cold mechanical reclamation of clay-bonded or chemically bonded sand using a grinding wheel |
Use of a rotating grinding wheel to remove clay layers and chemical binders from used sand grains. |
Generally applicable. |
f. |
Cold mechanical reclamation of sand using an impact drum |
Use of an impact drum with a spinning internal axis, equipped with small blades, for abrasive cleaning of sand grains. When applied on a mixture of bentonite and chemically bonded sand, a preliminary magnetic separation is carried out to remove parts with magnetic properties from the green sand. |
Generally applicable. |
g. |
Cold reclamation of sand using a pneumatic system |
Removal of binders from the sand grains using abrasion and impact. The kinetic energy is provided by a compressed air stream. |
Generally applicable. |
h. |
Thermal reclamation of sand |
Use of heat to burn binders and contaminants contained in chemically bonded and mixed sand. This is combined with an initial mechanical pretreatment to bring the sand to the correct grain size and remove any metallic contaminant. In the case of mixed sand, the share of chemically bonded sand should be high enough. |
May not be applicable in the case of used sand containing residues from inorganic binders. |
i. |
Combined reclamation (mechanical-thermal-mechanical) for mixed organic-bentonite sands |
After pretreatment (sieving, magnetic separation) and drying, sand is mechanically or pneumatically cleaned to remove part of the binder. In the thermal step, organic constituents are burned and inorganic constituents are transferred to the dust or burned onto the grains. In a final mechanical treatment, these grain layers are removed mechanically or pneumatically and discarded as dust. |
May not be applicable for core sands containing acidic binders (because it may alter bentonite characteristics) or in the case of water glass (because it may alter green sand characteristics). |
j. |
Combined sand reclamation and heat treatment of aluminium castings |
After pouring and solidification, moulds/casting units are loaded into the furnace. When the units reach a temperature > 420 °C, the binders are burnt, the cores/moulds disintegrate, and the castings undergo heat treatment. The sand falls to the bottom of the furnace for final cleaning in a heated fluidised bed. After cooling, the sand is reused in the core sand mixer without further treatment. |
Generally applicable. |
k. |
Wet reclamation for green sand, silicate- or CO2-bonded sands |
Sand is mixed with water to produce a sludge. The removal of grain-bound binder residues is performed through intensive inter-particle rubbing of the sand grains. The binders are released into the wash water. The washed sand is dried, screened and finally cooled. |
Generally applicable. |
l. |
Reclamation of sodium silicate sand (water glass) using a pneumatic system |
Sand is heated to make the silicate layer brittle before the use of a pneumatic system (see technique (g)). The reclaimed sand is cooled before reuse. |
Generally applicable. |
m. |
Internal reuse of core sand (cold-box or furan-acid binders) |
Sand resulting from broken/faulty cores, and excess sand from the core-making machines (after hardening in a specific unit), are fed to a breaking unit. The resulting sand is mixed with new sand for the production of new cores. |
Generally applicable. |
n. |
Reuse of dust from the green sand circuit in mould making |
Dust is collected through the exhaust filtration from the shake-out installation and from the dosing and handling stations for dry green sand. The collected dust (containing active binder compounds) can be recycled into the green sand circuit. |
Generally applicable. |
Foundry type |
Unit |
BAT-AEPL(26) (Yearly average) |
Cast iron foundries |
% |
> 90 |
Steel foundries |
> 80 |
|
NFM foundries(27) |
> 90 |
1.2.1.4.5.
Reduction of generated residues and of waste sent for disposal
BAT 19.
In order to reduce the amount of residues generated in metal melting and to reduce the amount of waste sent for disposal, BAT is to use all of the techniques given below.
Technique |
Description |
|||||||||||||||||
Techniques for all furnace types |
||||||||||||||||||
a. |
Minimisation of slag forming |
Slag forming can be minimised by in-process measures, such as:
|
||||||||||||||||
b. |
Mechanical pretreatment of slag / dross / filter dust / spent refractory linings to facilitate recycling |
See Section 1.4.2. This may also take place off site. |
||||||||||||||||
Techniques for cupola furnaces |
||||||||||||||||||
c. |
Adjustment of the slag acidity/basicity |
See Section 1.4.2. |
||||||||||||||||
d. |
Collection and recycling of coke breeze |
Coke breeze generated during handling, transport and charging of coke is collected (e.g. by using collection systems below conveyor belts and/or charging points) and recycled in the process (injected into the cupola furnace or used for recarburisation). |
||||||||||||||||
e. |
Recycling of filter dust in cupola furnaces using zinc-containing scraps |
Cupola filter dust is partially re-injected into the cupola furnace in order to increase the zinc content in the dust, up to a level that allows Zn recovery (> 18 %). |
||||||||||||||||
Techniques for EAFs |
||||||||||||||||||
f. |
Recycling of filter dust in the EAF |
Collected dry filter dust, usually after pretreatment (e.g. by pelletising or briquetting), is recycled in the furnace to enable the recovery of the metallic content of the dust. The inorganic content is transferred to the slag. |
BAT 20.
In order to reduce the amount of waste sent for disposal, BAT is to prioritise off-site recycling and/or other recovery over disposal for spent sand, undersize sand, slags, refractory linings and collected filter dust (e.g. fabric filter dust).
Description
Applicability
Waste type |
Unit |
BAT-AEPL(28) (Yearly average) |
||
NFM foundries |
Cast iron foundries |
Steel foundries |
||
Slag |
kg/t of liquid metal |
0 – 50 |
0 – 50 (2) |
0 – 50 (29) |
Dross |
0 – 30 |
0 – 30 |
0 – 30 |
|
Filter dust |
0 – 5 |
0 – 60 |
0 – 10 |
|
Spent furnace refractory linings |
0 – 5 |
0 – 20 (30) |
0 – 20 |
1.2.1.5.
Diffuse emissions to air
BAT 21.
In order to prevent or, where that is not practicable, to reduce diffuse emissions to air, BAT is to use all of the techniques given below.
Technique |
Description |
Applicability |
|||||||
a. |
Covering the delivery equipment (containers) and the cargo space of transport vehicles |
Cargo space of transport vehicles and delivery equipment (containers) are covered (e.g. with tarpaulins). |
Generally applicable. |
||||||
b. |
Cleaning roads and transport vehicle wheels |
Roads as well as the wheels of transport vehicles are regularly cleaned, e.g. by using mobile vacuum systems, water lagoons. |
Generally applicable. |
||||||
c. |
Using closed conveyors |
Materials are transferred using conveyor systems, e.g. closed conveyors, pneumatic conveying. Material drops are minimised. |
Generally applicable. |
||||||
d. |
Vacuum cleaning of moulding and casting process areas |
The moulding and casting process areas in sand moulding foundries are regularly vacuum-cleaned. |
May not be applicable in areas where the sand has a technical or safety-related function. |
||||||
e. |
Substitution of alcohol-based coatings with water-based coatings |
See Section 1.4.3. |
Applicability may be restricted in the case of large or complex casting shapes because of difficulties for circulation of the drying air. Not applicable to water-glass-bonded sands, the magnesium casting process, vacuum moulding or the production of manganese steel castings with MgO coating. |
||||||
f. |
Control of emissions from quenching baths |
This includes the following:
|
Generally applicable. |
||||||
g. |
Control of emission from transfer operations in metal melting |
This includes the following:
|
Generally applicable. |
1.2.1.6.
Channelled emissions to air
BAT 22.
In order to facilitate the recovery of materials and the reduction of channelled emissions to air, as well as to increase energy efficiency, BAT is to combine waste gas streams with similar characteristics, thus minimising the number of emission points.
Description
1.2.1.7.
Emissions to air from thermal processes
BAT 23.
In order to prevent or reduce emissions to air from metal melting, BAT is to use either electricity generated from fossil-free energy sources in combination with techniques (a) to (e), or techniques (a) to (e) and an appropriate combination of the techniques (f) to (i) given below.
|
Technique |
Description |
Applicability |
General techniques |
|||
a. |
Selection of an appropriate furnace type and maximisation of the thermal efficiency of furnaces |
See Section 4.4.1 |
The selection of an appropriate furnace type is only applicable to new plants and major plant upgrades. |
b. |
Use of clean scrap |
See Section 1.4.1 |
Generally applicable. |
Primary control measures to minimise PCDD/F emissions |
|||
c. |
Maximisation of the off-gases’ residence time and optimisation of the temperature in the post-combustion chamber in cupola furnaces |
In cupola furnaces, the temperature of the post-combustion chamber is optimised (T > 850 °C) and continuously monitored while the off-gases’ residence time is maximised (> 2 s). |
Generally applicable. |
d. |
Rapid off-gas cooling |
The off-gas is cooled rapidly from temperatures above 400 °C to below 250 °C before dust abatement to prevent the de novo synthesis of PCDD/F. This is achieved by appropriate design of the furnace and/or the use of a quench system. |
|
e. |
Minimising dust build-up in heat exchangers |
The build-up of dust along the cooling trajectory of the off-gases is minimised, especially in the heat exchangers, e.g. by using vertical exchanger tubes, efficient internal cleaning of the exchanger tubes, high-temperature de-dusting. |
|
Techniques for reducing the generation of NOX and SO2 emissions |
|||
f. |
Use of a fuel or a combination of fuels with low NOX formation potential |
Fuels with a low NOX formation potential include natural gas and liquefied petroleum gas. |
Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State. |
g. |
Use of a fuel or a combination of fuels with low sulphur content |
Fuels with low sulphur content include natural gas and liquefied petroleum gas. |
Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State. |
h. |
Low-NOX burners |
See Section 1.4.3. |
Applicability to existing plants may be restricted by furnace design and/or operational constraints. |
i. |
Oxy-fuel combustion |
See Section 1.4.3. |
Applicability to existing plants may be restricted by furnace design and the need for a minimum waste gas flow. |
BAT 24.
In order to prevent or reduce emissions to air from heat treatment, BAT is to use either electricity generated from fossil-free energy sources in combination with techniques (a) and (d), or all of the techniques given below.
|
Technique |
Description |
Applicability |
General techniques |
|||
a. |
Selection of an appropriate furnace type and maximisation of the thermal efficiency of furnaces |
See Section 1.4.3 |
Only applicable to new plants and major plant upgrades. |
Techniques for reducing the generation of NOX emissions |
|||
b. |
Use of a fuel or a combination of fuels with low NOX formation potential |
Fuels with a low NOX formation potential include natural gas and liquefied petroleum gas. |
Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State. |
c. |
Low-NOX burners |
See Section 1.4.3. |
Applicability to existing plants may be restricted by furnace design and/or operational constraints. |
Collection of emissions |
|||
d. |
Off-gas extraction as close as possible to the emission source |
Off-gases from heat treatment furnaces (e.g. annealing, ageing, normalising, austempering) are extracted using hoods or cover extraction. The collected emissions may be treated using techniques such as fabric filters. |
Generally applicable. |
Substance/Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
Indicative emission level (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5(31) |
No indicative level |
NOX |
20 – 120(32) (33) |
No indicative level |
|
CO |
No BAT-AEL |
10 – 100(33) |
1.2.1.8.
Emissions to air from moulding using lost moulds and core-making
BAT 25.
In order to prevent or reduce emissions to air from moulding using lost moulds and core-making, BAT is to:
|
Technique |
Description |
Applicability |
||||||||||||||||
Techniques for moulding with clay-bonded sand (green sand) |
|||||||||||||||||||
a. |
Use of best practices for green sand moulding |
This includes techniques such as:
|
Generally applicable. |
||||||||||||||||
b. |
Preparation of clay-bonded sand by vacuum mixing and cooling |
Mixing and cooling processes are combined into a single process step by operating the sand mixer under reduced pressure, which results in cooling by the controlled vaporisation of the water. |
Generally applicable. |
||||||||||||||||
c. |
Substitution of coal dust |
Coal dust is replaced by additives such as graphite, coke flour and zeolites, resulting in significantly lower diffuse emissions during the casting process. |
Applicability may be restricted by operational constraints (e.g. less efficient shake-out or occurrence of casting defects). |
||||||||||||||||
Techniques for prevention of emissions in moulding and core-making with chemically bonded sand |
|||||||||||||||||||
d. |
Selection of a low-emission cold-setting binder system |
A cold-setting binder system generating low emissions of formaldehyde, phenol, furfuryl alcohol, isocyanates, etc. is selected. This includes the use of:
|
Applicability may be restricted due to product specifications. |
||||||||||||||||
e. |
Selection of a low-emission gas curing binder system |
A gas curing binder system generating low emissions of amines, benzene, formaldehyde, phenol, isocyanates, etc. is selected. This includes the use of:
|
Applicability may be restricted due to product specifications. |
||||||||||||||||
f. |
Selection of a low-emission hot-curing binder system |
A hot-curing binder system generating low emissions of formaldehyde, phenol, furfuryl alcohol, benzene, isocyanates, etc. is selected. This includes the use of:
|
Applicability may be restricted due to product specifications. |
||||||||||||||||
General techniques for moulding and core-making with chemically bonded sand |
|||||||||||||||||||
g. |
Optimisation of binder and resin consumption |
See Section 1.4.3. |
Generally applicable. |
||||||||||||||||
h. |
Use of best practices for cold-setting processes |
See Section 1.4.3. |
Generally applicable. |
||||||||||||||||
i. |
Use of best practices for gas-hardening processes |
See Section 1.4.3. |
Generally applicable. |
||||||||||||||||
j. |
Use of non-aromatic solvents for cold-box core production |
Non-aromatic solvents are used that are based either on protein or animal fat (e.g. fatty acid methyl esters of vegetable oil) or on silicate esters in order to reduce emissions of VOCs (e.g. benzene, toluene). |
Generally applicable. |
||||||||||||||||
k. |
Use of best practices for hot-curing processes |
Several hot-curing processes may be used and a series of measures are in place to optimise each process including for the following: Hot-box process:
Warm-box process:
Shell (Croning):
The curing and/or core blower area is well ventilated and exhausted to capture the ammonia and formaldehyde liberated during curing efficiently. |
Generally applicable. |
||||||||||||||||
Techniques related to the coatings applied to moulds and cores |
|||||||||||||||||||
l. |
Substitution of alcohol-based coatings with water-based coatings |
See Section 1.4.3. |
Applicability may be restricted in the case of large or complex casting shapes because of difficulties for circulation of the drying air. Not applicable to water glass-bonded sands, the magnesium casting process, vacuum moulding or the production of manganese steel castings with MgO coating. |
BAT 26.
In order to reduce emissions to air from moulding using lost moulds and core-making, BAT is to:
|
Technique |
Description |
Applicability |
Collection of emissions |
|||
a. |
Extraction of emissions generated from moulding and/or core-making as close as possible to the emission source |
See Section 1.4.3. |
Applicability may be restricted in the case of moulding in cast iron and steel foundries producing large castings. |
Off-gas treatment |
|||
b. |
Fabric filter |
See Section 1.4.3. |
Generally applicable. |
c. |
Wet scrubbing |
See Section 1.4.3. |
Generally applicable. |
d. |
Adsorption |
See Section 1.4.3. |
Generally applicable. |
e. |
Thermal oxidation |
See Section 1.4.3. |
Applicability may be restricted where the energy demand is excessive due to the low concentration of the compound(s) concerned in the process off-gases. Applicability of recuperative and regenerative thermal oxidation to existing plants may be restricted by design and/or operational constraints. |
f. |
Catalytic oxidation |
See Section 1.4.3. |
Applicability may be restricted by the presence of catalyst poisons in the waste gases or where the energy demand is excessive due to the low concentration of the compound(s) concerned in the process off-gases. |
Substance/Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
||||||||
Dust |
mg/Nm3 |
1 – 5 |
||||||||
Amines |
< 0,5 – 2,5 (34) |
|||||||||
Benzene |
< 1 – 2 (35) |
|||||||||
Formaldehyde |
< 1 – 2 (36) |
|||||||||
Phenol |
< 1 – 2 (37) |
|||||||||
TVOC |
mg C/Nm3 |
15 – 50 (38) |
||||||||
|
1.2.1.9.
Emissions to air from casting, cooling and shake-out processes in foundries using lost moulds including the full mould process
BAT 27.
In order to reduce emissions to air from casting, cooling and shake-out processes in foundries using lost moulds including the full mould process, BAT is to:
Technique |
Description |
Applicability |
|||||||||||
Collection of emissions |
|||||||||||||
a. |
Extraction of emissions generated during the casting, cooling and shake-out processes as close as possible to the emission source |
Emissions generated during the casting (especially emissions from pouring), cooling and shake-out processes are appropriately extracted. For the casting and cooling processes, this includes:
For the shake-out process, this includes:
|
Applicability may be restricted in the case of cast iron and steel foundries producing large castings. |
||||||||||
Off-gas treatment |
|||||||||||||
b. |
Cyclone |
See Section 1.4.3. |
Generally applicable. |
||||||||||
c. |
Fabric filter |
See Section 1.4.3. |
Generally applicable. |
||||||||||
d. |
Wet scrubbing |
See Section 1.4.3. |
Generally applicable. |
||||||||||
e. |
Adsorption |
See Section 1.4.3. |
Generally applicable. |
||||||||||
f. |
Biofilter |
The off-gas stream is passed through a bed of organic material (such as peat, heather, compost, root, tree bark, softwood and different combinations) or some inert material (such as clay, activated carbon, and polyurethane), where it is biologically oxidised by naturally occurring microorganisms into carbon dioxide, water, inorganic salts and biomass. The biofilter is sensitive to dust, high temperatures and high variations in the off-gas composition. Supplementary nutrient feeding may be needed. |
Only applicable to the treatment of biodegradable compounds. |
||||||||||
g. |
Thermal oxidation |
See Section 1.4.3. |
Applicability of recuperative and regenerative thermal oxidation to existing plants may be restricted by design and/or operational constraints. Applicability may be restricted where the energy demand is excessive due to the low concentration of the compound(s) concerned in the process off-gases |
||||||||||
h. |
Catalytic oxidation |
See Section 1.4.3. |
Applicability may be restricted by the presence of catalyst poisons in the waste gases or where the energy demand is excessive due to the low concentration of the compound(s) concerned in the process off-gases. |
Substance/Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
Benzene |
< 1 – 2 (39) |
|
Formaldehyde |
< 1 – 2 (40) |
|
Phenol |
< 1 – 2 (41) |
|
TVOC |
mg C/Nm3 |
15 – 50 (42) |
1.2.1.10.
Emissions to air from lost foam casting
BAT 28.
In order to reduce dust and TVOC emissions to air from lost foam casting, BAT is to collect the emissions using technique (a) and to treat the off-gases by using an appropriate combination of the techniques (b) to (d) given below.
Technique |
Description |
Applicability |
|
Collection of emissions |
|||
a. |
Extraction of emissions generated from lost foam casting as close as possible to the emission source |
In the lost foam casting processes, emissions from the pyrolysis of the expanded polymer during pouring and shake-out are extracted using, for example an enclosure or a hood. |
Generally applicable. |
Off-gas treatment |
|||
b. |
Fabric filter |
See Section 1.4.3. |
Generally applicable. |
c. |
Wet scrubbing |
See Section 1.4.3. |
Generally applicable. |
d. |
Thermal oxidation |
See Section 1.4.3. |
Applicability of recuperative and regenerative thermal oxidation to existing plants may be restricted by design and/or operational constraints. Applicability may be restricted where the energy demand is excessive due to the low concentration of the compound(s) concerned in the process off-gases. |
Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
TVOC |
mg C/Nm3 |
15 – 50 (43) |
1.2.1.11.
Emissions to air from the casting process in foundries using permanent moulds
BAT 29
In order to prevent or reduce emissions to air from the casting process in foundries using permanent moulds, BAT is to:
Technique |
Description |
Applicability |
|||||
Prevention of emissions |
|||||||
a. |
General techniques for gravity and low-pressure die-casting |
This includes techniques such as
|
Generally applicable. |
||||
b. |
General techniques for high-pressure die-casting |
This includes techniques such as:
|
|||||
c. |
Optimisation of process parameters for centrifugal and continuous casting |
In centrifugal casting, important process parameters such as mould rotation, pouring temperature and mould preheating temperature are optimised (e.g. using flow simulation) to reduce the number of defects and minimise emissions. In continuous casting, the casting rate, casting temperature and cooling rate are optimised to minimise emissions and reduce the amount of water consumed for cooling while reaching the required product specification. |
|||||
d. |
Separate spraying of release agent and water in high-pressure die-casting |
See Section 1.4.2. |
|||||
e. |
Use of water-free release agents in high-pressure die-casting |
Water-free release agents (e.g. in a powdered form) are applied to the die using electrostatic deposition. |
|||||
Collection of emissions |
|||||||
f. |
Extraction of emissions generated from the casting process as close as possible to the emission source |
Emissions generated from the casting process including high-pressure/low-pressure/gravity die-casting, centrifugal and continuous casting are extracted using enclosures or extraction hoods. |
Generally applicable. |
||||
Off-gas treatment |
|||||||
g. |
Fabric filter |
See Section 1.4.3. |
Generally applicable. |
||||
h. |
Wet scrubbing |
See Section 1.4.3. |
|||||
i. |
Electrostatic precipitator |
See Section 1.4.3. |
|||||
j. |
Thermal oxidation |
See Section 1.4.3. |
Applicability of recuperative and regenerative thermal oxidation to existing plants may be restricted by design and/or operational constraints. Applicability may be restricted where the energy demand is excessive due to the low concentration of the compound(s) concerned in the process off-gases. |
Substance/Parameter |
Unit |
BAT-AELs (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
Pb |
0,05 – 0,1 (44) |
|
TVOC |
mg C/Nm3 |
2 – 30 (45) (46) |
1.2.1.12.
Emissions to air from finishing
BAT 30.
In order to reduce dust emissions to air from finishing, BAT is to collect the emissions using technique (a) and to treat the off-gases by using one or a combination of the techniques (b) to (d) given below.
Technique |
Description |
|||||||||
Collection of emissions |
||||||||||
a. |
Extraction of emissions generated from finishing as close as possible to the emission source |
Emissions generated from finishing operations, such as deburring, abrasive cutting, fettling, slide grinding, shot blasting, welding, chiselling, needling, are appropriately extracted using, e.g.:
|
||||||||
Off-gas treatment |
||||||||||
b. |
Cyclone |
See Section 1.4.3. |
||||||||
c. |
Fabric filter |
See Section 1.4.3. |
||||||||
d. |
Wet scrubbing |
See Section 1.4.3. |
Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
1.2.1.13.
Emissions to air from sand reuse
BAT 31.
In order to reduce emissions to air from sand reuse, BAT is to:
Technique |
Description |
Applicability |
|
Techniques for reducing the generation of emissions |
|||
a. |
Use of a fuel or a combination of fuels with low NOX formation potential |
Fuels with a low NOX formation potential include natural gas and liquefied petroleum gas. |
Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State. |
b. |
Use of a fuel or a combination of fuels with low sulphur content |
Fuels with low sulphur content include natural gas and liquefied petroleum gas. |
Applicable within the constraints associated with the availability of different types of fuel, which may be impacted by the energy policy of the Member State. |
Collection of emissions |
|||
c. |
Extraction of emissions generated from sand reuse as close as possible to the emission source |
Emissions generated from sand reclamation are extracted using an enclosure or a hood for example. This includes extraction of the flue-gases generated from fluidised bed furnaces, rotary kilns or hearth furnaces, etc. used in thermal sand regeneration. |
Generally applicable. |
Off-gas treatment |
|||
d. |
Cyclone |
See Section 1.4.3. |
Generally applicable. |
e. |
Fabric filter |
See Section 1.4.3. |
|
f. |
Wet scrubbing |
See Section 1.4.3. |
|
g. |
Thermal oxidation |
See Section 1.4.3. |
Applicability of recuperative and regenerative thermal oxidation to existing plants may be restricted by design and/or operational constraints. Applicability may be restricted where the energy demand is excessive due to the low concentration of the compound(s) concerned in the process off-gases. |
Substance/Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
TVOC |
mg C/Nm3 |
5 – 20 (47) |
Substance/Parameter |
Process |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
NOx |
Thermal regeneration of sand originating from the cold-box process |
mg/Nm3 |
50 – 140 |
SO2 |
Thermal regeneration of sand in which sulphonic acid catalysts have been used |
10 – 100 |
1.2.1.14.
Odour
BAT 32.
In order to prevent or, where that is not practicable, to reduce odour emissions, BAT is to set up, implement and regularly review an odour management plan, as part of the environmental management system (see BAT 1), that includes all of the following elements:
Applicability
BAT 33.
BAT is to periodically perform odour monitoring.
Description
Applicability
BAT 34.
In order to prevent or, where that is not practicable, to reduce odour emissions, BAT is to use all of the techniques given below.
Technique |
Description |
Applicability |
|||||
a. |
Substitution of chemicals containing alcohol-based or aromatic solvents |
This includes techniques such as:
|
Applicability of water-based coatings may be restricted due to the type of raw material or product specifications (e.g. big moulds/cores, water glass bonded sands, Mg castings, production of manganese steel with MgO coating). |
||||
b. |
Collection and treatment of amine emissions from the cold-box core-making process |
Off-gases containing amines, generated from the gassing of cold-box cores are extracted and treated using for example wet scrubbing, a biofilter, thermal or catalytic oxidation (see BAT 26). |
Generally applicable. |
||||
c. |
Collection and treatment of VOC emissions from chemically bonded sand preparation, pouring, cooling and shake-out |
Off-gases containing VOCs, generated from the preparation of chemically bonded sand, pouring, cooling and shake-out are extracted and treated using for example wet scrubbing, a biofilter, thermal or catalytic oxidation (see BAT 26). |
1.2.1.15.
Water consumption and waste water generation
BAT 35.
In order to optimise water consumption and to reduce the volume of waste water generated as well as to improve water recyclability, BAT is to use both techniques (a) and (b), and an appropriate combination of the techniques (c) to (g) given below.
Technique |
Description |
Applicability |
|||||||
a. |
Water management plan and audits |
A water management plan and audits are part of the EMS (see BAT 1) and include:
Audits are carried out at least once every year to ensure that the objectives of the water management plan are met and the audit recommendations are followed-up and implemented. |
The level of detail of the water management plan and audits will generally be related to the nature, scale and complexity of the plant. |
||||||
b. |
Segregation of water streams |
See Section 1.4.4. |
Applicability to existing plants may be restricted by the layout of the water collection system. |
||||||
c. |
Water reuse and/or recycling |
Water streams (e.g. process water, effluents from wet scrubbing, cooling water) are reused and/or recycled in closed or semi-closed circuits, if necessary after treatment (see BAT 36). |
The degree of water reuse and/or recycling is limited by the water balance of the plant, the content of impurities and/or the characteristics of the water streams. |
||||||
d. |
Prevention of waste water generation from process and storage areas |
See BAT 4 (b). |
Generally applicable. |
||||||
e. |
Use of dry dedusting systems |
This includes techniques such as fabric filters and dry ESPs (see Section 1.4.3). |
Generally applicable. |
||||||
f. |
Separate spraying of release agent and water in high-pressure die-casting |
See Section 1.4.2. |
Generally applicable. |
||||||
g. |
Use of waste heat for the evaporation of waste water |
When waste heat is available on a continuous basis, it can be used to evaporate waste water. |
Applicability may be restricted by the physico-chemical properties of the pollutants present in the waste water that can be emitted into the air. |
Foundry type |
Unit |
BAT-AEPL (Yearly average) |
Cast iron foundries |
m3/t of liquid metal |
0,5 – 4 |
Steel foundries |
||
Non-ferrous metal foundries (all types except HPDC) |
||
Non-ferrous metal HPDC foundries |
0,5 – 7 |
1.2.1.16.
Emissions to water
BAT 36.
In order to reduce emissions to water, BAT is to treat waste water using an appropriate combination of the techniques given below.
Technique(48) |
Typical pollutants targeted |
|
Preliminary, primary and general treatment, e.g. |
||
a. |
Equalisation |
All pollutants |
b. |
Neutralisation |
Acids, alkalis |
c. |
Physical separation through for example screens, sieves, grit separators, grease separators, hydrocyclones, oil-water separators or primary settlement tanks |
Gross solids, suspended solids, oil/grease |
Physico-chemical treatment, e.g. |
||
d. |
Adsorption |
Adsorbable dissolved non-biodegradable or inhibitory pollutants, e.g. hydrocarbons, mercury, AOX |
e. |
Chemical precipitation |
Precipitable dissolved non-biodegradable or inhibitory pollutants, e.g. metals, fluoride |
f. |
Evaporation |
Soluble contaminants, e.g. salts |
Biological treatment, e.g. |
||
g. |
Activated sludge process |
Biodegradable organic compounds |
h. |
Membrane bioreactor |
|
Solids removal, e.g. |
||
i. |
Coagulation and flocculation |
Suspended solids and particulate-bound metals |
j. |
Sedimentation |
Suspended solids and particulate-bound metals or non-biodegradable or inhibitory pollutants |
k. |
Filtration, e.g. sand filtration, microfiltration, ultrafiltration, reverse osmosis |
Suspended solids and particulate-bound metals |
l. |
Flotation |
Substance/Parameter |
Unit |
BAT-AEL(49) |
Origin of waste water stream(s) |
|
Adsorbable organically bound halogens (AOX)(50) |
mg/l |
0,1 – 1 |
Wet scrubbing of cupola off-gases |
|
Chemical oxygen demand (COD)(51) |
25 – 120 |
Die-casting, off-gas treatment (e.g. wet scrubbing), finishing, heat treatment, contaminated surface run-off water, direct cooling, wet sand regeneration and cupola furnace slag granulation. |
||
Total organic carbon (TOC)(51) |
8 – 40 |
|||
Total suspended solids (TSS) |
5 – 25 |
|||
Hydrocarbon oil index (HOI)(50) |
0,1 – 5 |
|||
Metals |
Copper (Cu)(50) |
0,1 – 0,4 |
||
Chromium (Cr)(50) |
0,1 – 0,2 |
|||
Lead (Pb)(50) |
0,1 – 0,3 |
|||
Nickel (Ni)(50) |
0,1 – 0,5 |
|||
Zinc (Zn)(50) |
0,5 – 2 |
|||
Phenol index |
0,05 – 0,5 (52) |
|||
Total nitrogen (TN)(50) |
1 – 20 |
Substance/Parameter |
Unit |
BAT-AEL(53) (54) |
Origin of waste water stream(s) |
|
Adsorbable organically bound halogens (AOX) (3) |
mg/l |
0,1 – 1 |
Wet scrubbing of cupola off-gases |
|
Hydrocarbon oil index (HOI)(55) |
0,1 – 5 |
Die-casting, off-gas treatment (e.g. wet scrubbing), finishing, heat treatment, contaminated surface run-off water, direct cooling, wet sand regeneration and cupola furnace slag granulation. |
||
Metals |
Copper (Cu)(55) |
0,1 – 0,4 |
||
Chromium (Cr)(55) |
0,1 – 0,2 |
|||
Lead (Pb)(55) |
0,1 – 0,3 |
|||
Nickel (Ni)(55) |
0,1 – 0,5 |
|||
Zinc (Zn)(55) |
0,5 – 2 |
|||
Phenol index |
0,05 – 0,5 (56) |
1.2.2.
BAT conclusions for cast iron foundries
1.2.2.1.
Energy efficiency
BAT 37.
In order to increase energy efficiency in metal melting, BAT is to use an appropriate combination of the techniques given below.
Technique |
Description |
Applicability |
|
a. |
Increase of shaft height in CBC furnaces |
See Section 1.4.1. |
Only applicable to new plants and major plant upgrades. Applicability to existing plants may be restricted by building and other structural constraints. |
b. |
Oxygen enrichment of the combustion air |
See Section 1.4.1. |
Generally applicable. |
c. |
Minimal blast shut-off periods for HBC furnaces |
See Section 1.4.1. |
Generally applicable. |
d. |
Long-campaign cupola |
See Section 1.4.1. |
Generally applicable. |
e. |
Post-combustion of off-gases |
See Section 1.4.1. |
Generally applicable. |
1.2.2.2.
Emissions to air from thermal processes
1.2.2.2.1.
Emissions to air from metal melting
BAT 38.
In order to prevent or reduce emissions to air from metal melting, BAT is to:
Technique |
Description |
Applicability |
|||||||||||||||||||||||||
Process-integrated techniques for cupola furnaces |
|||||||||||||||||||||||||||
a. |
Control of coke quality |
Coke is purchased based on important quality specifications (e.g. fixed carbon, ash, volatile matter, sulphur and moisture content, mean size diameter) which are systematically controlled before use. |
Generally applicable. |
||||||||||||||||||||||||
b. |
Adjustment of the slag acidity/basicity |
See Section 1.4.3. |
|||||||||||||||||||||||||
c. |
Increase of shaft height in CBC furnaces |
See Section 1.4.1. |
Only applicable to new plants and major plant upgrades. Applicability to existing plants may be restricted by building and other structural constraints. |
||||||||||||||||||||||||
d. |
Oxygen enrichment of the combustion air |
See Section 1.4.3. |
Generally applicable. |
||||||||||||||||||||||||
e. |
Long-campaign cupola |
See Section 1.4.1. |
Generally applicable. |
||||||||||||||||||||||||
Collection of emissions |
|||||||||||||||||||||||||||
f. |
Off-gas extraction as close as possible to the emission source |
In cupola furnaces, the off-gases are extracted either:
After extraction, the off-gases are cooled for example using:
For induction furnaces, off-gases are extracted, for example using:
For rotary furnaces, off-gases are extracted, for example using hood extraction. For EAFs, off-gases are extracted, for example using:
|
Generally applicable. |
||||||||||||||||||||||||
Off-gas treatment |
|||||||||||||||||||||||||||
g. |
Post-combustion of off-gases |
See Section 1.4.3. |
Generally applicable. |
||||||||||||||||||||||||
h. |
Cyclone |
See Section 1.4.3. |
Generally applicable. |
||||||||||||||||||||||||
i. |
Adsorption |
See Section 1.4.3. |
Generally applicable. |
||||||||||||||||||||||||
j. |
Dry scrubbing |
Dry powder or a suspension/solution of an alkaline reagent (e.g. lime or sodium bicarbonate) is introduced and dispersed in the off-gas stream. The material reacts with the acidic gaseous species (e.g. SO2) to form a solid which is removed by filtration (e.g. fabric filter). |
Generally applicable. |
||||||||||||||||||||||||
k. |
Fabric filter |
See Section 1.4.3. |
Generally applicable. |
||||||||||||||||||||||||
l. |
Wet scrubbing |
See Section 1.4.3. |
Generally applicable. |
Substance/Parameter |
Unit |
Furnace type |
BAT-AEL (Daily average or average over the sampling period) |
Indicative emission level (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
Induction, rotary, EAF |
1 – 5 |
No indicative emission level |
CBC, HBC |
1 – 7 (57) |
|||
HCl |
CBC, HBC |
10 – 30 (58) |
||
HF |
CBC, HBC, rotary furnaces |
1 – 3 (58) |
||
CO |
Rotary furnaces |
No BAT-AEL |
10 – 30 |
|
CBC, HBC |
No BAT-AEL |
20 – 220 |
||
NOX |
HBC |
20 –160 |
No indicative emission level |
|
CBC |
20 – 70 |
|||
Rotary furnaces |
20 – 100 |
|||
PCDD/F |
ng WHO-TEQ/Nm3 |
CBC, HBC, rotary furnaces |
< 0,01 – 0,08 |
|
Induction |
< 0,01 – 0,08 (59) |
|||
SO2 |
mg/Nm3 |
HBC |
30 – 100 |
|
Rotary furnaces |
10 – 50 |
|||
CBC |
50 – 150 |
|||
TVOC |
mg C/Nm3 |
All furnace types |
5 – 30 |
|
Pb |
mg/Nm3 |
CBC, HBC |
0,02 – 0,1 (59) |
1.2.2.2.2.
Emissions to air from the nodularisation of cast iron
BAT 39.
In order to prevent or reduce dust emissions to air from the nodularisation of cast iron, BAT is to use technique (a) or both of the techniques (b) and (c) given below.
Technique |
Description |
|
a. |
Nodularisation with no magnesium oxide emissions |
Use of the in-mould process whereby the magnesium alloy is added as a tablet, directly into the mould cavity, and the nodularisation reaction takes place during pouring. |
b. |
Off-gas extraction as close as possible to the emission source |
When magnesium oxide emissions are generated from the nodularisation technique used (e.g. sandwich, ductilator), off-gases are extracted as close as possible to the emission source using a fixed or movable extraction hood. |
c. |
Fabric filter |
See Section 1.4.3. The magnesium oxide collected may be reused for the production of pigments or refractory materials. |
Parameter |
Unit |
BAT-AEL(60) (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
1.2.3.
BAT conclusions for steel foundries
1.2.3.1.
Emissions to air from thermal processes
1.2.3.1.1.
Emissions to air from metal melting
BAT 40.
In order to prevent or reduce emissions to air from metal melting, BAT is to use both of the techniques given below.
Technique |
Description |
|||||||||||||||
Collection of emissions |
||||||||||||||||
a. |
Off-gas extraction as close as possible to the emission source |
The off-gases from induction furnaces are extracted, for example using:
The off-gases from EAFs are extracted, for example using:
|
||||||||||||||
Off-gas treatment |
||||||||||||||||
b. |
Fabric filter |
See Section 1.4.3. |
Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
PCDD/F |
ng WHO-TEQ / Nm3 |
< 0,01 – 0,08 (61) |
1.2.3.1.2.
Emissions to air from steel refining
BAT 41.
In order to reduce emissions to air from steel refining, BAT is to use both of the techniques given below.
Technique |
Description |
|
Collection of emissions |
||
a. |
Off-gas extraction as close as possible to the emission source |
Off-gases from steel refining (e.g. from Argon Oxygen Decarburisation (AOD) or Vacuum Oxygen Decarburisation (VOD) converters) are extracted using for example a direct extraction hood or a roof canopy combined with an accelerator stack. Extracted off-gases are treated using technique (b). |
Off-gas treatment |
||
b. |
Fabric filter |
See Section 1.4.3. |
Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
1.2.4.
BAT conclusions for non-ferrous metal foundries
1.2.4.1.
Energy efficiency
BAT 42.
In order to increase energy efficiency in metal melting, BAT is to use one of the techniques given below.
Technique |
Description |
|
a. |
Molten metal circulation in reverberatory furnaces |
A pump is installed on reverberatory furnaces to force the circulation of molten metal and minimise the temperature gradient throughout the molten bath (from top to bottom). |
b. |
Minimisation of energy losses by radiation in crucible furnaces |
Crucible furnaces are covered using a lid and/or equipped with radiant panel linings to minimise energy losses by radiation. |
1.2.4.2.
Emissions to air from thermal processes
1.2.4.2.1.
Emissions to air from metal melting
BAT 43.
In order to reduce emissions to air from metal melting, BAT is to collect the emissions using technique (a) and to treat the off-gases using one or a combination of the techniques (b) to (e) given below.
Technique |
Description |
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Collection of emissions |
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a. |
Off-gas extraction as close as possible to the emission source |
Off-gases from shaft, crucible, resistance, reverberatory (hearth-type) and radiant roof furnaces are extracted using hood extraction (e.g. canopy hoods). The extraction equipment is fitted in such a way that it enables the capture of emissions during pouring. Off-gases from induction furnaces are extracted, for example using:
Off-gases from rotary furnaces are extracted, for example using hood extraction. |
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Off-gas treatment |
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b. |
Cyclone |
See Section 1.4.3 |
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c. |
Dry scrubbing |
See Section 1.4.3 |
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d. |
Fabric filter |
See Section 1.4.3 |
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e. |
Wet scrubbing |
See Section 1.4.3 |
Substance/Parameter |
Unit |
BAT-AEL (Daily average or average over the sampling period) |
Indicative emission level (Daily average or average over the sampling period) |
Dust |
mg/Nm3 |
1 – 5 |
No indicative emission level |
HCl |
1 – 3 (62) (67) |
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HF |
< 1 (62) |
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CO |
No BAT-AEL |
5 – 30 (63) (64) |
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NOX |
20 – 50 (65) (66) |
No indicative emission level |
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PCDD/F |
ng WHO-TEQ/Nm3 |
< 0,01 – 0,08 (67) |
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SO2 |
mg/Nm3 |
< 10 (65) (68) |
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Pb |
< 0,02 – 0,1 (69) |
1.2.4.3.
Emissions to air from the treatment and protection of molten metal
BAT 44.
It is not BAT to use chlorine gas for molten aluminium treatment (degassing/cleaning).
BAT 45.
In order to prevent emissions of substances with a high global warming potential from the protection of molten metal in magnesium melting, BAT is to use oxidation control agents with a low global warming potential.
Description
1.3.
BAT conclusions for smitheries
1.3.1.
Energy efficiency
BAT 46.
In order to increase energy efficiency in heating/reheating and heat treatment, BAT is to use all the techniques given below.
Technique |
Description |
Applicability |
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a. |
Optimisation of furnace design |
This includes techniques such as:
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Only applicable to new plants and major plant upgrades. |
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b. |
Furnace automation and control |
See Section 1.4.1. |
Generally applicable. |
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c. |
Optimisation of feedstock heating/reheating |
This includes techniques such as:
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Generally applicable. |
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d. |
Preheating of combustion air |
See Section 1.4.1. |
Applicability to existing plants may be restricted by a lack of space for the installation of regenerative burners. |
Sector |
Unit |
Indicative level (Yearly average) |
Smitheries |
kWh/t of feedstock |
1 700 – 6 500 |
1.3.2.
Material efficiency
BAT 47.
In order to increase the material efficiency and to reduce the quantity of waste sent for disposal, BAT is to use all of the techniques given below.
Technique |
Description |
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a. |
Process optimisation |
This includes techniques such as:
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b. |
Optimisation of raw and auxiliary material consumption |
This includes techniques such as:
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c |
Recycling of process residues |
Process residues (e.g. metallic residues from the processes of preparation of raw materials, hammering and finishing; used shot blast media) are recycled and/or reused. |
1.3.3.
Vibrations
BAT 48.
In order to reduce vibrations occurring from the hammering process, BAT is to use vibration-reducing and insulating techniques.
Description
Applicability
1.3.4.
Monitoring of emissions to air
BAT 49.
BAT is to monitor channelled emissions to air with at least the frequency given below, and in accordance with EN standards. If EN standards are not available, BAT is to use ISO, national or other international standards that ensure the provision of data of an equivalent scientific quality.
Substance/Parameter |
Specific process |
Standard(s) |
Minimum monitoring frequency(70) |
Monitoring associated with |
Nitrogen oxides (NOX) |
Heating/reheating, heat treatment |
EN 14792 |
Once every year |
BAT 50 |
Carbon monoxide (CO) |
Heating/reheating, heat treatment |
EN 15058 |
1.3.5.
Emissions to air
1.3.5.1.
Diffuse emissions to air
BAT 50.
In order to prevent or reduce diffuse emissions to air, BAT is to use both of the techniques given below.
Technique |
Description |
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a. |
Operational and technical measures |
This includes techniques such as:
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b. |
Extraction of emissions from shot blasting |
Emissions from shot blasting. Extracted off-gases are treated using techniques such as fabric filters. |
1.3.5.2.
Emissions to air from heating/reheating and heat treatment
BAT 51.
In order to prevent or reduce NO
X
emissions to air from heating, reheating and heat treatment while limiting CO emissions, BAT is to use either electricity generated from fossil-free energy sources or an appropriate combination of the techniques given below.
Technique |
Description |
Applicability |
|
a. |
Use of a fuel or a combination of fuels with low NOX formation potential |
Fuels with a low NOX formation potential include natural gas and liquefied petroleum gas. |
Generally applicable. |
b. |
Combustion optimisation |
Measures taken to maximise the efficiency of energy conversion in the furnace while minimising emissions (in particular of CO). This is achieved by a combination of techniques including good design of the furnace, optimisation of the temperature (e.g. efficient mixing of the fuel and combustion air) and residence time in the combustion zone, and use of furnace automation and control. |
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c. |
Furnace automation and control |
See Section 1.4.1. |
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d. |
Flue-gas recirculation |
Recirculation (external) of part of the flue-gas to the combustion chamber to replace part of the fresh combustion air, with the dual effect of lowering the temperature and limiting the O2 content for nitrogen oxidation, thus limiting the NOX generation. It implies the supply of flue-gas from the furnace into the flame to reduce the oxygen content and therefore the temperature of the flame. |
Applicability to existing plants may be restricted by a lack of space. |
e. |
Low-NOX burners |
See Section 1.4.3. |
Applicability to existing plants may be restricted by design and/or operational constraints. |
f. |
Limiting the temperature of air preheating |
Limiting the air preheating temperature leads to a decrease of the concentration of NOX emissions. A balance has to be achieved between maximising heat recovery from the flue-gas and minimising NOX emissions. |
Generally applicable. |
g. |
Oxy-fuel combustion |
See Section 1.4.3. |
Applicability to existing plants may be restricted by furnace design and the need for a minimum waste gas flow. |
h. |
Flameless combustion |
See Section 1.4.3. |
Applicability to existing plants may be restricted by furnace design (i.e. furnace volume, space for burners, distance between burners) and the need for a change of the furnace refractory lining. Not applicable to furnaces operating at a temperature lower than the auto-ignition temperature required for flameless combustion. |
Parameter |
Unit |
Process(es) |
BAT-AEL (Daily average or average over the sampling period) |
Indicative emission level (Daily average or average over the sampling period) |
NOX |
mg/Nm3 |
Heating / reheating / heat treatment |
100 – 250 (71) |
No indicative level |
CO |
Heating / reheating / heat teatment |
No BAT-AEL |
10 – 100 |
1.3.6.
Water consumption and waste water generation
BAT 52.
In order to optimise water consumption and to reduce the volume of waste water generated, BAT is to use both of the techniques (a) and (b) given below:
Technique |
Description |
Applicability |
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a. |
Segregation of water streams |
See Section 1.4.4. |
Applicability to existing plants may be restricted by the layout of the water collection system. |
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b. |
Water reuse and/or recycling |
Water streams (e.g. process water, cooling water) are reused and/or recycled in closed or semi-closed circuits, if necessary after treatment. |
The degree of water reuse and/or recycling is limited by the water balance of the plant, the content of impurities and/or the characteristics of the water streams. |
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1.4.
Descriptions of techniques
1.4.1.
Techniques to increase energy efficiency
Technique |
Description |
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Furnace automation and control |
The heating process is optimised by using a computer system controlling key parameters such as furnace and feedstock temperature, the air to fuel ratio and the furnace pressure. |
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Improving casting yield and decreasing scrap generation |
Measures are taken to maximise the efficiency of the casting process and to decrease the generation of scrap, e.g.:
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Increase of shaft height in CBC furnaces |
Increasing the shaft height in cold blast cupola furnaces enables combustion gases to remain in contact with the charge for longer, resulting in a higher heat transfer. |
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Long-campaign cupola |
The cupola furnace is set up for long campaign operation to minimise maintenance and process changes. This may be achieved by using more resistant furnace refractory linings in the shaft, bottom and hearth, by using water cooling of the furnace wall and with water-cooled blasting pipes penetrating deeper into the furnace shaft. |
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Minimal blast shut-off periods for HBC furnaces |
Minimisation of blast shut-off periods by programming the schedules of the moulding and casting processes to ensure a reasonably constant demand for metal. |
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Oxy-fuel combustion |
Combustion air is replaced fully or partially with pure oxygen. Oxy-fuel combustion can be used in combination with flameless combustion. |
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Oxygen enrichment of the combustion air |
Oxygen enrichment of the combustion air is realised either directly at the blast supply or through injection of oxygen into the coke bed, or via the tuyères. |
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Post-combustion of off-gases |
See Section 1.4.3. |
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Preheating of combustion air |
Reuse of part of the heat recovered from the combustion flue-gas to preheat the air used in combustion. This may be achieved for example by using regenerative or recuperative burners (see below). A balance has to be achieved between maximising heat recovery from the flue-gas and minimising NOX emissions. |
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Recuperative burner |
Recuperative burners employ different types of recuperators (e.g. heat exchangers with radiation, convection, compact or radiant tube designs) to directly recover heat from the flue-gases, which are then used to preheat the combustion air. |
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Regenerative burner |
Regenerative burners consist of two burners which are operated alternately and which contain beds of refractory or ceramic materials. While one burner is in operation, the heat of the flue-gas is absorbed by the refractory or ceramic materials of the other burner and then used to preheat the combustion air. |
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Selection of an energy-efficient type of furnace |
Furnace energy efficiency is taken into consideration for the furnace selection, e.g. furnaces that allow the preheating and drying of incoming charge prior to the melting zone. |
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Techniques for maximising the thermal efficiency of furnaces |
Measures taken to maximise the efficiency of energy conversion in melting and heat treatment furnaces while minimising emissions (in particular of dust and CO). This is achieved by applying a series of process optimisation measures according to the furnace type including optimisation of the temperature (e.g. efficient mixing of the fuel and combustion air) and residence time in the combustion zone, and use of furnace automation and control (see above). Measures for some specific furnaces include the following: For cupola furnaces:
For induction furnaces:
For rotary furnaces:
For EAFs:
For shaft furnaces:
For reverbatory furnaces:
For crucible furnaces:
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Use of clean scrap |
Melting clean scrap prevents the risk of non-metal compounds being taken up by the slag and/or degrading the furnace or ladle refractory linings. |
1.4.2.
Techniques to increase material efficiency
Technique |
Description |
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Adjustment of the slag acidity/basicity |
Use of an appropriate flux (e.g. limestone for acidic and calcium fluoride for basic cupola operations) to render the slag fluid enough to separate from the iron. |
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Improving casting yield and decreasing scrap generation |
See Section 1.4.1. |
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Mechanical pretreatment of slag / dross / filter dust / spent refractory linings to facilitate recycling |
Generated slag / dross / filter dust / spent refractory linings are pretreated on site, by using techniques such as crushing, segregation, granulation, magnetic separation. |
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Optimisation of binder and resin consumption |
Measures to optimise binder and resin consumption include:
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Separate spraying of release agent and water in high-pressure die-casting |
Water and release agents are applied separately to the mould using an additional row of nozzles mounted on the spray head. Water is sprayed first, leading to a significant cooling of the mould before the application of the release agent, which results in reduced emissions and consumption of release agents and water. |
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Use of best practices for cold-setting processes |
Practices include the following (according to the binding system used):
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Use of best practices for gas-hardening processes |
Practices include the following (according to the hardening process used): For phenolic urethane resins (cold-box process):
For resol-ester resins:
For CO2-hardened resins (e.g. alkaline phenolic, silicate):
For SO2-hardened resins (e.g. phenolic, epoxy/acrylic):
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Use of clean scrap |
See Section 1.4.1. |
1.4.3.
Techniques to reduce emissions to air
Technique |
Description |
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Adjustment of the slag acidity/basicity |
See Section 1.4.2. |
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Adsorption |
The removal of pollutants from a process off-gas or waste gas stream by retention on a solid surface (activated carbon is typically used as the adsorbent). Adsorption may be regenerative or non-regenerative. |
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Catalytic oxidation |
Abatement technique which oxidises combustible compounds in a waste gas stream with air or oxygen in a catalyst bed. The catalyst enables oxidation at lower temperatures and in smaller equipment compared to thermal oxidation. The typical oxidation temperature is between 200 °C and 600 °C. |
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Cyclone |
Equipment for the removal of dust from an off-gas stream based on imparting centrifugal forces, usually within a conical chamber. Cyclones are mainly used as a pretreatment before further dust abatement or abatement of organic compounds. Multicyclones may also be used. |
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Dry scrubbing |
Dry powder or a suspension/solution of an alkaline reagent (e.g. lime or sodium bicarbonate) is introduced and dispersed in the off-gas stream. The material reacts with the acidic gaseous species (e.g. SO2) to form a solid, which is removed by filtration (e.g. fabric filter). |
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Electrostatic precipitator |
Electrostatic precipitators (ESPs) operate such that particles are charged and separated under the influence of an electrical field. Electrostatic precipitators are capable of operating under a wide range of conditions. Abatement efficiency may depend on the number of fields, residence time (size), and upstream particle removal devices. They generally include between two and five fields, but may contain up to seven fields for the most advanced ESPs. Electrostatic precipitators can be of the dry or of the wet type depending on the technique used to collect the dust from the electrodes. Wet ESPs are typically used at the polishing stage to remove residual dust and droplets after wet scrubbing. |
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Extraction of emissions generated from moulding and/or core-making as close as possible to the emission source |
Emissions generated from moulding (including the making of patterns) and/or core-making are extracted. The extraction system selected depends on the type of moulding/core-making process.
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Fabric filter |
Fabric filters, often referred to as bag filters, are constructed from porous woven or felted fabric through which gases are passed to remove particles. Fabric filters can be in the form of sheets, cartridges or bags with a number of the individual fabric filter units housed together in a group. The use of a fabric filter requires the selection of a fabric suitable for the characteristics of the waste gas and the maximum operating temperature. |
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Flameless combustion |
Flameless combustion is achieved by injecting fuel and combustion air separately into the combustion chamber of the furnace at high velocity to suppress flame formation and reduce the formation of thermal NOX while creating a more uniform heat distribution throughout the chamber. Flameless combustion can be used in combination with oxy-fuel combustion (see Section 1.4.1). |
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Furnace automation and control |
See Section 1.4.1. |
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Low-NOX burner |
The technique (including ultra-low-NOX burners) is based on the principles of reducing peak flame temperatures. The air/fuel mixing reduces the availability of oxygen and reduces the peak flame temperature, thus retarding the conversion of fuel-bound nitrogen to NOX and the formation of thermal NOX, while maintaining high combustion efficiency. |
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Optimisation of binder and resin consumption |
See Section 1.4.2. |
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Oxygen enrichment of the combustion air |
See Section 1.4.1. |
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Oxy-fuel combustion |
See Section 1.4.1. |
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Post-combustion of off-gases |
Post-combustion of CO and other organic compounds contained in furnace off-gases is used to reduce emissions and for heat recovery. The generated heat is recovered with a heat exchanger and used for blast air preheating or other internal purposes. In HBC furnaces, post-combustion takes place in a separate post-combustion chamber preheated by a natural gas burner. In CBC furnaces, post-combustion takes place directly in the cupola shaft. In rotary furnaces, post-combustion is carried out using an afterburner installed between the furnace and the heat exchanger. |
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Selection of an appropriate furnace type |
Selection of the appropriate furnace type(s) based on the level of emissions and technical criteria, e.g. type of process such as continuous or batch production, furnace capacity, type of castings, availability of raw materials, flexibility depending on raw materials’ cleanliness and alloy change. The energy efficiency of the furnace is also considered (see technique ‘Selection of an energy-efficient type of furnace’ in Section 1.4.1). |
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Substitution of alcohol-based coatings with water-based coatings |
Substitution of alcohol-based coatings of moulds and cores with aqueous coatings. Aqueous coatings are dried in ambient air or using drying ovens. |
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Thermal oxidation |
Abatement technique which oxidises combustible compounds in a waste gas stream by heating it with air or oxygen to above its auto-ignition point in a combustion chamber and maintaining it at a high temperature long enough to complete its combustion to carbon dioxide and water. The typical combustion temperature is between 800 °C and 1 000 °C. Several types of thermal oxidation are operated:
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Use of best practices for cold-setting processes |
See Section 1.4.2. |
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Use of best practices for gas-hardening processes |
See Section 1.4.2. |
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Wet scrubbing |
The removal of gaseous or particulate pollutants from a gas stream via mass transfer to a liquid solvent, often water or an aqueous solution. It may involve a chemical reaction (e.g. in an acid or alkaline scrubber). In some cases, the compounds may be recovered from the solvent. This includes venturi scrubbers. |
1.4.4.
Techniques to reduce emissions to water
Technique |
Description |
Activated sludge process |
In the activated sludge process, the microorganisms are maintained as a suspension in the waste water and the whole mixture is mechanically aerated. The activated sludge mixture is sent to a separation facility from which the sludge is recycled to the aeration tank. |
Adsorption |
The removal of soluble substances (solutes) from the waste water by transferring them to the surface of solid, highly porous particles (typically activated carbon). |
Aerobic treatment |
The biological oxidation of dissolved organic pollutants with oxygen using the metabolism of microorganisms. In the presence of dissolved oxygen, injected as air or pure oxygen, the organic components are mineralised into carbon dioxide and water or are transformed into other metabolites and biomass. |
Chemical precipitation |
The conversion of dissolved pollutants into an insoluble compound by adding chemical precipitants. The solid precipitates formed are subsequently separated by sedimentation, air flotation or filtration. If necessary, this may be followed by microfiltration or ultrafiltration. Multivalent metal ions (e.g. calcium, aluminium, iron) are used for phosphorus precipitation. |
Chemical reduction |
The conversion of pollutants by chemical reducing agents into similar but less harmful or hazardous compounds. |
Coagulation and flocculation |
Coagulation and flocculation are used to separate suspended solids from waste water and are often carried out in successive steps. Coagulation is carried out by adding coagulants with charges opposite to those of the suspended solids. Flocculation is carried out by adding polymers, so that collisions of microfloc particles cause them to bond to produce larger flocs. |
Equalisation |
Balancing of flows and pollutant loads at the inlet of the final waste water treatment by using central tanks. Equalisation may be decentralised or carried out using other management techniques. |
Evaporation |
Evaporation of waste water is a distillation process where water is the volatile substance, leaving the concentrate as bottom residue to be handled (e.g. recycled or disposed of). The aim of this operation is to reduce the volume of waste water or to concentrate mother liquors. The volatile steam is collected in a condenser and the condensed water is, if necessary after subsequent treatment, recycled. There are many types of evaporators: natural circulation evaporators; short-tube vertical evaporators; basket-type evaporators; falling film evaporators; agitated thin film evaporators. Typical pollutants targeted are soluble contaminants (e.g. salts). |
Filtration |
The separation of solids from waste water by passing them through a porous medium, e.g. sand filtration, microfiltration and ultrafiltration. |
Flotation |
The separation of solid or liquid particles from waste water by attaching them to fine gas bubbles, usually air. The buoyant particles accumulate at the water surface and are collected with skimmers. |
Membrane bioreactor (MBR) |
MBR consists of the combination of a membrane process (e.g. microfiltration or ultrafiltration) with a suspended growth bioreactor. In an MBR system for biological waste water treatment, the secondary clarifier and the tertiary filtration step of a traditional aerated sludge system is replaced by membrane filtration (the separation of sludge and suspended solids). |
Nanofiltration |
A filtration process in which membranes with pore sizes of approximately 1 nm are used. |
Neutralisation |
The adjustment of the pH of waste water to a neutral level (approximately 7) by the addition of chemicals. Sodium hydroxide (NaOH) or calcium hydroxide (Ca(OH)2) is generally used to increase the pH, whereas sulphuric acid (H2SO4), hydrochloric acid (HCl) or carbon dioxide (CO2) is generally used to decrease the pH. The precipitation of some substances may occur during neutralisation. |
Physical separation |
The separation of gross solids, suspended solids, metal particles from the waste water using for example screens, sieves, grit separators, grease separators, hydrocyclones, oil-water separation or primary settlement tanks. |
Reverse osmosis |
A membrane process in which a pressure difference applied between the compartments separated by the membrane causes water to flow from the more concentrated solution to the less concentrated one. |
Sedimentation |
The separation of suspended particles and suspended material by gravitational settling. |
Segregation of water streams |
Water streams (e.g. surface run-off water, process water) are collected separately, based on the pollutant content and on the required treatment techniques. Waste water streams that can be recycled without treatment are segregated from waste water streams that require treatment. |