Reducing benzo(a)pyrene pollution in metallurgical centers

The environment of metallurgical centers is polluted with such a highly toxic carcinogenic substance as benzo(a)pyrene, the concentration of which in the air can reach 20-150 MAC. It is formed during the combustion of all types of carbon fuel, but in maximum quantities during the combustion of solid energy sources. Benzo(a)pyrene accumulates and remains for a long time in various components of the environment, making it toxic. Monitoring of its content in various environments is carried out by chromatographic analysis of selected samples, and continuous monitoring of its emissions is impossible. Coke batteries, in which coal is coked at low temperatures and with a lack of air, have the highest emissions of benzo(a)pyrene. Large emissions of benzo(a) pyrene are associated with the agglomeration process, iron pouring in blast furnace and steelmaking production, and combustion of process gases in flare stacks. It is possible to reduce benzo(a)pyrene emissions from metallurgical units mainly through proper organization of the technological process. During charge agglomeration, its emissions can be reduced by balanced air supply to the sintered layer and organization of gas circulation between the sintering and cooling zones.In cokemaking, for this purpose it is necessary to prevent coke gas leaks from batteries and along the entire gas tract. In blast furnace and steelmaking production, all iron pouring should be carried out under covers with gas extraction from them and their supply for dust cleaning. It is necessary to abandon the combustion of process gases in flare stacks and ensure their complete collection and use as fuel, during combustion of which benzo(a)pyrene will decompose. The most effective way to capture benzo(a)pyrene is to remove it from the flow together with dust, on the particles of which it is sorbed. The thermal method of its decomposition in flues by passing it through a burner flame is applicable only to flue gases of heating furnaces and cupolas. The use of catalytic, plasma-chemical, biochemical and other methods of decomposing hydrocarbons in the exhaust gases of metallurgical units is highly expensive due to their large volumes, and can only be recommended for cleaning ventilation gases.