Annex 25 Complementary information to source category 2j Other Non-ferrous Metal Production
Overview of recent revisions
No revisions of emission factors have been made. Additional guidance has been introduced on classifying sources within this category, estimating activity rates, and on data quality aspects.
Derivation of emission factors
Release to Air
Work in Norway showed that a process carried out to refine primary nickel, which used a fluidized bed reactor at 800°C to convert NiCl2 to NiO, had polluted the environment heavily with PCDD/PCDF but no emission factors were given (Oehme et al. 1989). Tests in Germany have identified high emissions from tin smelting (up to 113 μg TEQ/t) but insufficient information is provided to be able to apply this emission factor to tin production processes in general (Bröker et al. 1999).
Other thermal metal processes can release PCDD/PCDF and emissions will be influenced by the degree of contamination on the scrap materials and the capture and treatment of the flue gases. Lowest emissions can be expected where the raw materials are clean and gas treatment comprehensive – including dust control by fabric filters, lime injection and possibly activated carbon addition and in some cases an afterburner.
Emissions will be high for installations with poor controls on input materials leading to high concentrations. Even if mass flow is small, local contamination may result. The emission factors are estimated based on patchy data on thermal non-ferrous metal recovery, concentrations would vary widely from well under 1 ng/m³ (class 2) to tens of ng/m³ (class 1).
Release to Water
Releases to water may occur where effluents are discharged. The presence and source of effluents should be noted.
Release to Land
No release is expected except where residues are dumped on land.
Release in Products
No PCDD/PCDF is expected in refined metal products.
Release in Residues
Residues may contain PCDD/PCDF. Insufficient data were available to estimate emissions factors. The use of a residue as a raw material could lead to contamination of the subsequent process.