Research on Dioxin Formation in Thermal, Industrial, Metallurgical and Incineration Processes

摘要

Since it was discovered that thermal metallurgical processes, especially secondary metal smelters and the sintering belt are an important source of dioxins, PAHs and other persistent organic pollutants (POPs), measures to reduce emissions were taken both by the iron and steel industry and by the non-ferrous sector. The best practice includes a combination of primary preventive measures aiming to improve burn out of gases and fly ash, and secondary abatement measures, e.g. adsorption on activated carbon or catalytic destruction. However, a better understanding of the mechanisms of dioxin formation is needed, which should contribute to the development and optimization of technologies for minimizing the formation and the release of these compounds in the environment. The major problems in dioxin research are the rapidly changing and very low concentrations of these compounds, and the large number of possible factors influencing them. Individual variations of dioxin emissions from different metallurgical processes are related to the nature of the catalytic system, carbon structures, operating conditions amount and composition of paniculate and gas. This paper provides brief background on the formation mechanisms, outlines technical measures applicable for dioxin abatement and introduces a case study of the problem solution in a copper smelter.