Sinter plants are associated with iron manufacture, often in integrated iron and steel mills. The sintering process is a pre-treatment step in the production of iron where fine particles of metal ores are agglomerated by combustion. A detailed description of the iron sintering processes and the related abatement techniques is given in the BAT&BEP Guidelines.

The waste gas flow from a sinter plant varies from 350,000 to 1,600,000 Nm³/hour, depending on the plant size and operating conditions. Typically the specific waste gas flow is between 1,500 and 2,500 Nm³/t of sinter (BREF 2012). Waste gases are usually treated by dust removal in a cyclone, electrostatic precipitator, wet scrubber or fabric filter. In plants where high PCDD/PCDF emissions have been identified, high performance scrubbing systems may be installed to reduce emissions, coupled with measures to reduce gas flows.

Extensive research into formation of PCDD/PCDF in the sintering process has shown that they are formed within the sinter bed itself, probably just ahead of the flame front as hot gases are drawn through the bed. It has also been shown that de novo formation of PCDD/PCDF in the gas collectors from reactive fine dust particles is responsible for approximately 10% of the total PCDD/PCDF and that primary measures to prevent PCDD/PCDF formation should be taken in the sinter bed. Besides input-related measures, disruptions to flame front propagation, i.e. non-steady state operations, result in higher PCDD/PCDF emissions (Nordsieck et al. 2001). Thus, operating the sintering process as consistent as possible in terms of strand speed, bed composition, bed height, use of additives, and keeping the strand, ductwork and ESP air tight to minimize, as far as possible, the amount of air ingress in the operation will result in less PCDD/PCDF formation.

Emission Factors

PCDD/PCDF emission factors for three source classes are listed in Table II.2.3. Revised or newly added emission factors are highlighted in red. Emission factors for other unintentional POPs are listed in Annex 16. Detailed information on how default emission factors have been derived can also be found in Annex 16.

Table II.2.3 PCDD/PCDF emission factors for source category 2a Iron Ore Sintering

2a	Iron Ore Sintering	Emission Factors (µg TEQ/t sinter produced)
Classification		Air	Water	Land	Product	Residue*
1	High waste recycling including oil contaminated materials, no or limited air pollution control system	20	ND	ND	NA	0.003
2	Low waste use, well controlled plant	5	ND	ND	NA	1
3	High technology emission reduction	0.3	ND	ND	NA	2

* Residues: these emission factors are based on an assumption of 0.05 kg dust/t sinter released (i.e., not internally recycled).

Guidance for Classification of Sources

Class 1 includes plants with high use of waste, including cutting oils or other chlorinated contaminants, and limited process control and no or limited air pollution control system.
Class 2 should be applied for those plants that show good combustion control and have little use of waste, in particular cutting oils.
Class 3 should be used for those plants which have taken comprehensive measures to control PCDD/PCDF and comply with the BAT&BEP Guidelines.

Very low technology sintering plants may have higher emissions. Any plants found with poor combustion controls and very limited air pollution control systems should be noted for future examination.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information, including iron and steel production;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

PCDD/PCDF emission factors for iron ore sintering are provided:

• With a high level of confidence for class 2 and class 3 air emissions, as emission factors are derived from a broad geographical coverage and are based on a low data range and not on expert judgment;
• With a medium level of confidence for class 1 air emissions and class 3 residue releases, as emission factors are based on a low data range and not on expert judgment but are not derived from a broad geographical coverage;
• With a low level of confidence for class 1 and 2 residues releases, as emission factors are based on extrapolations and expert judgment.

Coke is produced from hard coal or brown coal by carbonization (heating under vacuum). In “coke ovens”, coal is charged into large vessels, which are subjected to external heating to approximately 1,000°C in the absence of air. Coke is removed and quenched with water. The major use of coke is in the iron and steel industry.

No data are available to estimate releases from the production of charcoal from wood. This process can be carried out in many small units, which taken together may represent a considerable production. For initial estimates of emissions, the emission factors given in this section for simple plants should be applied (class 1).

Emission Factors

PCDD/PCDF emission factors for two source classes are listed in Table II.2.4. Revised or newly added emission factors are highlighted in red. Emission factors for other unintentional POPs are listed in Annex 17. Detailed information on how default emission factors have been derived can also be found in Annex 17.

Table II.2.4 PCDD/PCDF emission factors for source category 2b Coke Production

2b	Coke Production	Emission Factors (µg TEQ/t coke produced)
Classification		Air	Water	Land	Product	Residue*
1	No gas cleaning	3	0.06*	NA	ND	ND
2	APC with afterburner/ dust removal	0.03	0.06*	NA	ND	ND

* Use factor of 0.006 µg TEQ/t where water treatment is applied.

Guidance for Classification of Sources

Class 1 should be applied to facilities where no dust removal device is in use.
Class 2 should be used for plants using technology such as an afterburner and dust removal equipment.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information, including iron and steel production;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For coke production, PCDD/PCDF emission factors are provided with a medium level of confidence for all classes, as emission factors are based on a low data range, they are not based on expert judgment, but are derived from a limited geographical coverage.

The iron and steel industry is a highly material intensive industry with raw materials such as ores, pellets, scrap, coal, lime, limestone (in some cases also heavy oil and plastics) and additives and auxiliaries. It is also highly energy-intensive. More than half of the mass input becomes outputs in the form of releases to air and solid wastes or by-products. The most relevant emissions are those to air, with the emissions from sinter plants dominating the overall emissions for most pollutants (see source category 2a).

In this section, all processes used in the manufacture of iron and steel are covered. Four routes are currently used for the production of steel: the classic blast furnace/basic oxygen furnace route, direct melting of scrap (electric arc furnace), smelting reduction and direct reduction (BREF 2012). For the purpose of the Toolkit, a categorization can be done according to the type of input material: blast furnaces (BF) are used only for the production of pig iron and are fed with iron ores from either sintering plants or pelletizing plants. Blast furnaces do not utilize scrap. Scrap is being used in electric arc furnaces (EAF), Basic Oxygen Furnaces (BOF) as well as in foundries where cupola furnaces (CF) and induction furnaces (IF) are found.

The hot-dip galvanizing process is included in this section since its objective is to protect steel from corrosion.

Five types of furnaces are commonly used to melt metals in foundries: cupola, electric arc, induction, reverberatory, and crucible. As no information is currently identified regarding foundry processes for die casting of non-ferrous metal alloys, which include induction furnaces, reverberatory or crucible for instance, emission factors of the “iron foundries” section may be used as default factors for such non-ferrous foundry processes.

The various furnace types and processes are described in the BAT&BEP Guidelines.

Emission Factors

PCDD/PCDF emission factors for eleven source classes grouped by activity type are listed in Table II.2.5. Revised or newly added emission factors are highlighted in red. Emission factors for other unintentional POPs are listed in Annex 18. Detailed information on how default emission factors have been derived can also be found in Annex 18.

Table II.2.5 PCDD/PCDF emission factors for source category 2c Iron and Steel Production Plants

2c	Iron and Steel Production Plants	Emission Factors (µg TEQ/t LS)
Classification		Air	Water	Land	Product	Residue
Iron and Steel Making
1	Dirty scrap (cutting oils, general contamination), scrap preheating, limited controls	10	ND	NA	NA	15
2	Clean scrap/virgin iron or dirty scrap, afterburner and fabric filter	3	ND	NA	NA	15
3	Clean scrap/virgin iron or dirty scrap, EAF equipped with APC designed for low PCDD/PCDF emission, BOF furnaces	0.1	ND	NA	NA	0.1
4	Blast furnaces with APCS	0.01	ND	NA	NA	ND
Iron Foundries
1	Cold air cupola or hot air cupola or rotary drum with no gas cleaning	10	NA	NA	NA	ND
2	Rotary Drum - fabric filter or wet scrubber	4.3	NA/ND*	NA	NA	0.2
3	Cold air cupola – fabric filter or wet scrubber	1	NA/ND*	NA	NA	8
4	Hot air cupola or induction furnace and fabric filter or wet scrubber	0.03	NA/ND*	NA	NA	0.5
Hot-dip Galvanizing Plants - Emission Factors (µg TEQ/t of galvanized iron/steel)
1	Facilities without APCS	0.06	NA	NA	NA	0.01
2	Facilities without degreasing step, good APCS (bagfilters)	0.05	NA	NA	NA	2
3	Facilities with degreasing step, good APCS (bagfilters)	0.02	NA	NA	NA	1

* ND where wet scrubbers are used

Guidance for Classification of Sources

In the iron and steel making category:

Class 1 includes all iron and steel making processes (such as electric arc furnaces and open hearth furnaces), except basic oxygen furnaces and blast furnaces, using dirty scrap containing cutting oils or plastic materials and plants with scrap preheating and relatively poor controls;
Class 2 includes all iron and steel making processes (such as electric arc furnaces and open hearth furnaces), except basic oxygen furnaces and blast furnaces, using dirty scrap or clean scrap or virgin iron that are fitted with some after-burners and fabric filters for gas cleaning;
Class 3 includes electric arc furnaces using dirty scrap or clean scrap or virgin iron and efficient gas cleaning with secondary combustion and fabric filters (sometimes in combination with a rapid water quench), and basic oxygen furnaces;
Class 4 should be used for blast furnaces with air pollution control systems.

In the iron foundries category:

Class 1 includes cold air cupolas or hot air cupola or rotary drum furnaces without fabric filters or equivalent for gas cleaning;
Class 2 includes rotary drum furnaces with fabric filters or wet scrubbers;
Class 3 includes cold air cupolas with fabric filters or wet scrubbers;
Class 4 includes hot air cupolas and induction furnaces fitted with fabric filters or wet scrubbers.

In the hot-dip galvanizing plants category:

Class 1 includes facilities without air pollution control systems;
Class 2 includes facilities with good air pollution control systems but without a degreasing step;
Class 3 includes facilities with both air pollution control systems and a degreasing step.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For iron and steel making, emission factors for PCDD/PCDF are provided:

• With a high level of confidence for air emissions (all classes) and for class 2 residue releases, as emission factors are derived from a broad geographical coverage and are based on a low data range and not on expert judgment;
• With a medium level of confidence for residue releases related to classes 1 and 3, as emission factors are not based on expert judgment but are not derived from a broad geographical coverage.

For iron foundries, emission factors for PCDD/PCDF are provided:

• With a medium level of confidence for air emissions and for class 4 residue releases, as emission factors are not based on expert judgment but are not derived from a broad geographical coverage;
• With a low level of confidence for class 2 and 3 residue releases, as emission factors are based on extrapolations and expert judgment.

For hot-dip galvanizing plants, emission factors for PCDD/PCDF are provided:

• With a medium level of confidence for air emissions, as emission factors are not based on expert judgment but are not derived from a broad geographical coverage;
• With a low level of confidence for residue releases, as emission factors are based on extrapolations and expert judgment.

Thermal copper (Cu) generation and releases of PCDD/PCDF are of special interest, as copper is the most efficient metal to catalyze the formation of PCDD/PCDF. When analyzing the copper production sector for PCDD/PCDF releases, it is important to differentiate between primary and secondary production.

Primary copper

Primary copper may be produced by two different technologies depending on the type of minerals treated, either oxides or sulfides, and from primary concentrates and other materials either by pyrometallurgical or hydrometallurgical routes (BREF 2009). Hydrometallurgical methods are applied to treat oxidized minerals, i.e. leaching, solvent extraction, and electrowinning. All these processes are operated at temperatures below 50°C. It is not expected that formation of PCDD/PCDF will occur. Typically, sulfurized minerals are treated by the pyrometallurgical route. Sulphidic minerals are first treated in a concentration plant, operated at room temperature, and then the concentrates are pyrometallurgically refined in primary copper smelters. The concentrates to be smelted consist basically of copper and iron sulfides and are low in chlorine (ppm). The stages involved are roasting, smelting, converting, refining, and electrorefining. The smelting process is performed in an oxidizing atmosphere at temperatures between 1,200°C and 1,300°C. Further process details are described in the BAT&BEP Guidelines.

Secondary copper

Secondary copper is produced by pyrometallurgical processes and is obtained from scrap or other copper-bearing residues such as slags and ashes. Since used copper can be recycled without loss of quality, secondary copper production is an important sector. An overview of secondary raw materials for copper production and a description of relevant processes can be found in the BAT&BEP Guidelines.

Emission Factors

PCDD/PCDF emission factors for six source classes are listed in Table II.2.6. In order to harmonize the Toolkit with the BAT&BEP Guidelines, where BAT consideration is given for primary base metal smelters, class 6 - pure primary Cu smelters with no secondary feed materials - is also included in the Toolkit. However, in the absence of measured data, there will be no default emission factor provided for this class.

Emission factors for other unintentional POPs are listed in Annex 19. Revised or newly added emission factors are highlighted in red. Detailed information on how default emission factors have been derived can also be found in Annex 19.

Table II.2.6 PCDD/PCDF emission factors for source category 2d Copper Production

2d	Copper Production	Emission Factors (µg TEQ/t copper)
Classification		Air	Water	Land	Product	Residue
1	Sec. Cu – Basic Technology	800	0.5	NA	NA	630
2	Sec. Cu – Well controlled	50	0.5	NA	NA	630
3	Sec. Cu –Optimized for PCDD/PCDF control	5	0.5	NA	NA	300
4	Smelting and casting of Cu/Cu alloys	0.03	0.5	NA	NA	ND
5	Prim. Cu, well-controlled, with some secondary feed materials	0.01	0.5	NA	NA	ND
6	Pure primary Cu smelter with no secondary feed materials	ND	0.5	NA	NA	NA

Guidance for Classification of Sources

Class 1 should be applied to thermal processing of mixed materials where furnaces are equipped with simple fabric filters, no or less effective air pollution control systems.
Class 2 will be used where thermal processing of scrap copper materials is carried out in furnaces that are well controlled and fitted, with afterburners and fabric filters. The scrap should undergo some sorting and classification prior to processing to minimize contaminants.
Class 3 should be used for plants where measures have been taken to address releases of PCDD/PCDF, such as installation of rapid water quench prior to the fabric filters, and activated carbon used in the flue gas treatment.
Class 4 addresses the smelting and casting of copper and copper alloys.
Class 5 should be taken for primary Cu, well controlled plants with some secondary feed materials.
Class 6 includes primary copper smelters that use clean raw materials and use either the base smelting process or the flash smelting. The releases from primary copper smelters that recycled secondary materials such as copper scrap or other residues can be estimated by applying the emission factor for class 5. For this class, the ‘’pure’’ primary copper smelters, there are no emission factors presently available.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For copper production, emission factors for PCDD/PCDF are provided:

• With a high level of confidence for class 2 and 5 air emissions, as emission factors are derived from a broad geographical coverage and are based on a low data range and not on expert judgment;
• With a medium level of confidence for water releases, for classes 1, 3 and 4 air emissions and for classes 2 and 3 residue releases, as emission factors are not based on expert judgment but are not derived from a broad geographical coverage;
• With a low level of confidence for class 1 residue releases, as emission factors are based on extrapolations and expert judgment.

Aluminum (Al) can be produced from aluminum ore, most commonly bauxite (primary production), or from scrap (secondary production). In primary aluminum production, the mined aluminum ore (e.g., bauxite) is refined into aluminum oxide trihydrate (alumina) through the Bayer Process. The alumina is then electrolytically reduced into metallic aluminum through the Hall-Héroult Process, which utilizes either self-baking anodes, the Söderberg anodes, or pre-baked anodes. The use of pre-baked anodes represents the most modern process. Further process information can be found in the BAT&BEP Guidelines.

Primary aluminum production is generally thought not to be a significant source of unintentionally produced POPs. However PCDD/PCDF formation and release is possible through the graphite-based electrodes used in the electrolytic smelting process.

Emission Factors

PCDD/PCDF emission factors for six source classes are listed in Table II.2.7. Revised or newly added emission factors are highlighted in red. Emission factors for other unintentional POPs are listed in Annex 20. Detailed information on how default emission factors have been derived can also be found in Annex 20.

Table II.2.7 PCDD/PCDF emission factors for source category 2e Aluminum Production

2e	Aluminum Production	Emission Factors (µg TEQ/t aluminum)
Classification		Air	Water	Land	Product	Residue
1	Thermal processing of scrap Al, minimal treatment of inputs and simple dust removal	100	ND	NA	NA	200
2	Thermal Al processing, scrap pre-treatment, well-controlled, fabric filters with lime injection	3.5	ND	NA	NA	400
3	Optimized for PCDD/PCDF control – afterburners, lime injection, fabric filters and active carbon	0.5	ND	NA	NA	100
4	Shavings/turning drying (simple plants)	5	NA	NA	NA	NA
5	Thermal de-oiling of turnings, rotary furnaces, afterburners, and fabric filters	0.3	NA	NA	NA	NA
6	Pure primary Al production	ND	NA	NA	NA	ND

Guidance for Classification of Sources

Class 1 should be used for plants with simple or no dust removal equipment.
Class 2 should be used for plants that have scrap pre-treatment, afterburners and dust control (e.g. fabric filters), other air pollution controls but no specific dioxin treatment.
Class 3 should be used where high efficiency controls are in place consisting of scrap cleaning, afterburners, fabric filters with lime and specific dioxin treatment (activated carbon injection).
Class 4 applies to the drying of Al shavings and turnings in rotary drums or similar equipment.
Class 5 applies to thermal de-oiling of turnings in rotary kilns with afterburners and fabric filters.
Class 6 refers to primary aluminum production by electrolysis and ingot smelting.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For aluminum production, emission factors for PCDD/PCDF are provided:

• With a high level of confidence for class 2 air emissions, as emission factors are derived from a broad geographical coverage and are based on a low data range and not on expert judgment;
• With a medium level of confidence for all other classes (air and residue vectors), as emission factors are based on a low data range but are not derived from a broad geographical coverage.

Two main routes for primary lead production from sulfide ores are available – sintering/smelting and direct smelting. Emissions from direct smelting are low and not considered further (SCEP 1994).

Considerable quantities of lead are recovered from scrap materials, in particular vehicle batteries. A variety of furnace designs are used, including rotary furnaces, reverberatory, crucible, shaft, blast and electric furnaces. Continuous direct smelting processes may be used.

PCDD/PCDF emissions may be linked to high organic matter and the presence of chlorine in scrap materials; in particular, a link between the use of PVC separators in vehicle batteries and PCDD/PCDF emissions has been made.

Emission Factors

PCDD/PCDF emission factors for four source classes are listed in Table II.2.8.Revised or newly added emission factors are highlighted in red. Emission factors for other unintentional POPs are listed in Annex 21. Detailed information on how default emission factors have been derived can also be found in Annex 21.

Table II.2.8 PCDD/PCDF emission factors for source category 2f Lead Production

2f	Lead Production	Emission Factors (µg TEQ/t lead)
Classification		Air	Water	Land	Product	Residue
1	Lead production from scrap containing PVC	80	ND	NA	NA	ND
2	Lead production from PVC/Cl2 free scrap, some APCS	8	ND	NA	NA	50
3	Lead production from PVC/Cl2 free scrap in highly efficient furnaces, with APC including scrubbers	0.05	ND	NA	NA	ND
4	Pure primary lead production	0.4	NA	NA	NA	ND

Guidance for Classification of Sources

Class 1 Secondary lead production from scrap containing PVC, no air pollution control system.
Class 2 Secondary lead production from PVC/Cl2 free scrap, some air pollution control system.
Class 3 Lead production from PVC/Cl2 free scrap in highly efficient furnaces, with air pollution control systems including wet scrubbers.
Class 4 Pure primary lead production.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For lead production, emission factors for PCDD/PCDF are provided:

• With a high level of confidence for class 2 air emissions and residue releases, as emission factors are derived from a broad geographical coverage and are based on a low data range and not on expert judgment;
• With a medium level of confidence for classes 1, 3 and 4 air emissions, as emission factors are based on a low data range but are not derived from a broad geographical coverage.

Zinc may be recovered from ores through a variety of processes. The co-occurrence of lead and zinc ores means that there may be a considerable overlap between these two sectors. Crude zinc may be produced in combination with a lead ore blast furnace or be recovered from the slag from such processes in rotary kilns. A variety of scrap materials may be used for zinc recovery as well as secondary raw materials such as dusts from copper alloy production, electric arc steel-making (e.g., filter dusts and sludge), residues from steel scrap shredding, scrap from galvanizing processes. The zinc production process from secondary raw materials can be done in a zinc recovery rotary kiln (Waelz kiln), which is up to 95 m long with internal diameters of around 4.5 m; they are lined with refractory material.

The processing of impure scrap such as the non-metallic fraction from shredders is likely to involve production of pollutants, including PCDD/PCDF. Relatively low temperatures are used to recover lead and zinc (340 and 440°C). Melting of zinc may occur with the addition of fluxes including zinc and magnesium chlorides. Further process information can be found in the BAT&BEP Guidelines.

Emission Factors

PCDD/PCDF emission factors for four source classes are listed in Table II.2.9. Revised or newly added emission factors are highlighted in red. Emission factors for other unintentional POPs are listed in Annex 22. Detailed information on how default emission factors have been derived can also be found in Annex 22.

Table II.2.9 PCDD/PCDF emission factors for source category 2g Zinc Production

2g	Zinc Production	Emission Factors (µg TEQ/t zinc)
Classification		Air	Water	Land	Product	Residue
1	Kiln with no APCS	1,000	ND	NA	NA	0.02
2	Hot briquetting/rotary furnaces, basic dust control; e.g., fabric filters/ESP	100	ND	NA	NA	1*
3	Comprehensive air pollution controls, e.g., fabric filters with active carbon/DeDiox technology	5	ND	NA	NA	1*
4	Zinc melting and primary zinc production	0.1	ND	NA	NA	ND

* In some cases (e.g. Waelz kilns) emission factors can be as high as 2,000 µg TEQ/ t of zinc

Guidance for Classification of Sources

Class 1 Rotary kiln with no air pollution control system.
Class 2 Hot briquetting/rotary furnaces equipped with basic dust control (e.g., fabric filters/electrostatic precipitators).
Class 3 Secondary zinc production with comprehensive air pollution control systems (e.g., fabric filters with active carbon/DeDiox technology).
Class 4 Zinc melting and primary zinc production.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For zinc production, emission factors for PCDD/PCDF are provided:

• With a high level of confidence for classes 2 and 3 air emissions, as emission factors are derived from a broad geographical coverage and are based on a low data range and not on expert judgment;
• With a medium level of confidence for other classes and/or vectors, as emission factors are not based on expert judgment but are not derived from a broad geographical coverage.

Brass is a hard yellow shiny metal that is an alloy of copper (55%-90%) and zinc (10%-45%). The properties of brass vary with the proportion of copper and zinc and with the addition of small amounts of other elements, such as aluminum, lead, tin, or nickel. In general, brass can be forged or hammered into various shapes, rolled, etc. Brass can be produced by either re-melting the brass scrap or melting stoichiometric amounts of copper and zinc together. In principle, either one or both can be primary or secondary metal.

Bronze is a hard yellowish-brown alloy of copper and tin, phosphorus, and sometimes small amounts of other elements. Bronze is harder than copper and brass. Bronze is often cast to make statues. Most bronze is produced by melting the copper and adding the desired amounts of tin, zinc, and other substances. The properties of the alloy depend on the proportions of its components.

Brass and bronze can be produced in simple, relatively small melting pots or in more sophisticated equipment such as induction furnaces equipped with air pollution control systems.

Emission Factors

PCDD/PCDF emission factors for four source classes are listed in Table II.2.10. Emission factors for other unintentional POPs are listed in Annex 23. Detailed information on how default emission factors have been derived can also be found in Annex 23.

Table II.2.10 PCDD/PCDF emission factors for source category 2h Brass and Bronze Production

2h	Brass and Bronze Production	Emission Factors (µg TEQ/t brass/bronze)
Classification		Air	Water	Land	Product	Residue
1	Thermal de-oiling of turnings, afterburner, wet scrubber	2.5	NA	NA	NA	NA
2	Simple melting furnaces	10	ND	NA	NA	ND
3	Mixed scrap, induction furnaces, fabric filters	3.5	ND	NA	NA	125
4	Sophisticated equipment, e.g. induction ovens with APCS	0.1	ND	NA	NA	ND

Guidance for Classification of Sources

Class 1 should be used for plants which are more elaborated than class 2 furnaces, e.g. induction ovens equipped with baghouse filters and wet scrubbers and/or de-oiling of turnings.
Class 2 should be used for simple smelting furnaces equipped with some flue gas abatement technology, e.g. scrubber or electrostatic precipitators.
Class 3 includes induction furnaces using mixed scrap and equipped with fabric filters.
Class 4 includes more sophisticated equipment such as induction ovens with APCS.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For brass and bronze production, emission factors for PCDD/PCDF are provided:

• With a high level of confidence for classes 1, 3 and 4 air emissions, as emission factors are derived from a broad geographical coverage and are based on a low data range and not on expert judgment;
• With a medium level of confidence for other classes and/or vectors, as emission factors are not based on expert judgment but are not derived from a broad geographical coverage.

The production of magnesium from ores is largely based on either electrolysis of MgCl2 or chemical reduction of oxidized magnesium compounds. The raw materials used are dolomite, magnesite, carnallite, brines or seawater depending on the process. Magnesium can also be recovered and produced from a variety of magnesium-containing secondary raw materials.

The electrolysis process is more widely used. This process seems to be of most interest from the point of view of PCDD/PCDF formation and release. Secondary magnesium production is not addressed in this section.

In the thermal reduction process, calcined dolomite is reacted with ferro-silicon sometimes together with aluminum in a furnace or retort vessel. The calcination process takes place by decarbonization and dehydration of dolomite limestone. For the calcination process of dolomite, often a rotate or vertical furnace is used. Further process information can be found in the BAT&BEP Guidelines.

Emission Factors

PCDD/PCDF emission factors for three source classes are listed in Table II.2.11. Emission factors for other unintentional POPs are listed in Annex 24. Detailed information on how default emission factors have been derived can also be found in Annex 24.

Table II.2.11 PCDD/PCDF emission factors for source category 2i Magnesium Production

2i	Magnesium Production	Emission Factors (µg TEQ/t magnesium)
Classification		Air	Water	Land	Product	Residue
1	Production using MgO/C thermal treatment in Cl2 – no treatment on effluent, limited gas treatment	250	9,000	NA	NA	0
2	Production using MgO/C thermal treatment in Cl2 – comprehensive pollution control	50	30	NA	NA	9,000
3	Thermal reduction process	3	ND	NA	NA	NA

Guidance for Classification of Sources

Class 1 Production processes using MgO and coke thermal treatment in Cl2 atmosphere, without treatment of wastewater and with limited gas treatment.
Class 2 Production processes using MgO and coke thermal treatment in Cl2 atmosphere with comprehensive pollution control.
Class 3 Thermal reduction process.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For magnesium production, emission factors for PCDD/PCDF are provided:

• With a high level of confidence for class 2 air and water releases and for class 3, as emission factors are derived from a broad geographical coverage and are based on a low data range and not on expert judgment;
• With a medium level of confidence for class 2 residue releases and for class 1, as emission factors are not based on expert judgment but are not derived from a broad geographical coverage.

A number of non-ferrous metals are not assigned to a specific category in the Toolkit: cadmium, precious metals, chromium, nickel, ferro-alloys (FeSi, FeMn, SiMn, etc.), alkali metals, etc. A variety of processes are undertaken to produce and refine non-ferrous metals. The exact processes used and the propensity to form PCDD/PCDF are complex and not studied in detail. It is important not to miss potentially significant PCDD/PCDF sources simply because data are insufficient to provide comprehensive emissions factors. Therefore, to provide an initial indication of potential releases, it is suggested that processes in non-ferrous metal production are examined. Releases may occur to air, water, and in residues. When investigating production processes, it is suggested that thermal processes are noted, the type of gas cleaning system applied recorded, and the levels of contamination found in the input materials noted. The use of Cl2 or hexachloroethane for refining, and the presence of chlorinated compounds in raw materials should also be noted. The Questionnaire provided in the Toolkit will assist in identifying and recording these parameters.

In the case of these non-ferrous metals, a 3-step approach is proposed:

1. First step: some non-ferrous metals are produced in conjunction with metals which are assigned to a specific category in the toolkit. In that case, the corresponding emission factors should be considered. For example:
   • Cadmium may be produced in conjunction with lead or zinc. Emission factors of category 2f (class 4) or category 2g (class 4) should be considered.
   • Precious metals may be produced in conjunction with copper or lead. Emission factors of category 2d (classes 5 or 6) or category 2f (class 4) should be considered.
2. Second step: some non-ferrous metals are produced in processes similar to other processes which are assigned to a specific category or class in the toolkit. In that case, the corresponding emission factors should be considered. For example, ferro-alloys are usually produced in electric arc furnaces similar to those used in the iron and steel sector, hence emission factors of category 2c should be considered. Another example are zinc alloys (e.g. zamak) which can be produced similarly to bronze and brass. Therefore, emission factors of category 2h, if appropriate classes apply, can be used as default values.
3. Finally, if a given non-ferrous metal cannot be considered under the first or the second step, emission factors of category 2j should be used.

Emission Factors

PCDD/PCDF emission factors for two source classes are listed in Table II.2.12. Detailed information on how these emission factors have been derived can be found in Annex 25.

Table II.2.12 PCDD/PCDF emission factors for source category 2j Other Non-Ferrous Metal Production

2j	Other Non-Ferrous Metal Production	Emission Factors (µg TEQ/t product)
Classification		Air	Water	Land	Product	Residue
1	Thermal non-ferrous metal processes – contaminated scrap, simple or no APCS	100	ND	NA	NA	ND
2	Thermal non-ferrous metal processes – clean scrap, fabric filters/lime injection/afterburners	2	ND	NA	NA	ND

Guidance for Classification of Sources

Class 1Thermal non-ferrous metal processes utilizing contaminated scrap with simple or no air pollution control systems.
Class 2Thermal non-ferrous metal processes utilizing clean scrap and air pollution control systems such as fabric filters, lime injection and afterburners.

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For other non-ferrous metals production, emission factors for PCDD/PCDF are provided with a low level of confidence, as they are based on expert judgment and are not derived from a broad geographical coverage. However, given the wide range of situations (raw materials, industrial processes) under this source category, emission factors may be process-specific.

When talking about shredders, usually automobile shredders are mentioned. Other feedstock is also accepted; in practice, much light scrap such as bicycles, office furniture, vending machines and so-called “white” goods, e.g., refrigerators, stoves, washing machines, etc., and “brown” goods, e.g., television sets, radios, etc., are fed into shredders (Nijkerk and Dalmijn 2001). Shredders are large-scale machines, which are equipped inside with one or more anvil(s) or breaker bar(s) and lined with alloy steel wear plates. Details on the process can be found in the BAT&BEP Guidelines.

Shredder plants for treatment of end of life vehicles are listed in Annex C of the Convention as a source that has the potential to form and release unintentional POPs. However, at present there is not sufficient evidence that in this mechanical process PCDD/PCDF or PCB are newly formed. The data available indicate that PCDD/PCDF and PCBs released from shredder plants are from industrial/intentional PCB production and have been introduced with oils, dielectric fluids, etc. contained in such vehicles or consumer goods. The shredders simply set free these contaminants.

Based on this information, one single class of emission factors is used for releases from the shredding process itself.

Emission Factors

PCDD/PCDF emission factors for one source class are listed in Table II.2.13. Revised or newly added emission factors are highlighted in red. PCB emission factors are listed in Annex 26. Detailed information on how default emission factors have been derived can also be found in Annex 26.

Table II.2.13 PCDD/PCDF emission factors for source category 2k Shredders

2k	Shredders	Emission Factors (µg TEQ/t recovered steel)
Classification		Air	Water	Land	Product	Residue
1	Metal shredding plants	0.2	NA	NA	ND	5

Activity rates

Activity rates may be obtained from various sources, such as the following:

• Owners/operators of the relevant facilities (by questionnaires);
• State, provincial, national and/or international agencies that gather centralized statistical information;
• State, provincial and national agencies that issue permits;
• Other release inventories such as the inventory of mercury sources and releases, criteria pollutants and/or greenhouse gases;
• International statistics such as EUROSTAT, OECD, FAO, World Bank, etc.

Level of Confidence

For shredders, PCDD/PCDF emission factors to air are provided with a high level of confidence, as they are derived from a broad geographical coverage and are based on a low data range and not on expert judgment. PCDD/PCDF emission factors for residues releases are provided with a low level of confidence, as they are based on extrapolations and expert judgment.

Burning of cable is the process in which copper is recovered from wire by burning the insulating material. In its most basic form, this process takes place in the open and consists of scrap wire, which is burned to remove wire coverings. In many countries this would be considered to be an illegal operation. More sophisticated operations would use a furnace with gas clean-up consisting of afterburners and scrubbers. In this process, all ingredients to form PCDD/PCDF are present: carbon (sheath), chlorine (PVC or mould resistant agents) and a catalyst (copper).

Emission Factors

PCDD/PCDF emission factors for four source classes are listed in Table II.2.14. Revised or newly added emission factors are highlighted in red. Emission factors for other unintentional POPs are listed in Annex 27. Detailed information on how default emission factors have been derived can also be found in Annex 27.

Table II.2.14 PCDD/PCDF emission factors for source category 2l Thermal Wire Reclamation and E-Waste Recycling

2l	Thermal Wire Reclamation and E-Waste Recycling	Emission Factors (µg TEQ/t material)
Classification		Air	Water	Land	Product	Residue
1	Open burning of cable	12,000	ND	ND	ND	ND
2	Open burning of circuit boards	100	ND	ND	ND	ND
3	Basic furnace with afterburner and wet scrubber	40	ND	NA	ND	ND
4	Burning electric motors and brake shoes, etc. – afterburner fitted	3.3	ND	NA	ND	ND

Guidance for Classification of Sources

Class 1 includes open burning of wire, not conducted at dedicated industrial sites related to category 2d.
Class 2 includes factors for open burning of circuit boards, especially in the case of e-waste recycling.
Class 3 factors should be used for controlled operations to recover wire using a furnace with basic gas cleaning, i.e., for cable burning in furnaces fitted with afterburners and wet scrubbers.
Class 4 factors should be used for furnaces used to recover electric motor windings, brake shoes and the like with some gas cleaning system fitted.

Activity rates

It may be necessary to estimate the amount of wire burned in the open since it is unlikely that statistics will be kept. Sites where this process occurs can usually be identified due to the residue that remains.

Level of Confidence

For thermal wire reclamation and e-waste recycling, emission factors for PCDD/PCDF and for PCB are provided with a medium level of confidence, as emission factors are not based on expert judgment but are not derived from a broad geographical coverage.