Multilayer composite pellet for inhibiting SO2 and NOx in sintering process

Abstract

The invention discloses a multilayer composite pellet for inhibiting SO2 and NOx in a sintering process, and belongs to the technical field of pollutant emission reduction in the sintering process. The pellet comprises an inner-layer pellet and an outer-layer pellet arranged outside the inner-layer pellet. The inner-layer pellet comprises an ammonia inhibitor and an inner-layer pelletizing material, and the ammonia inhibitor can release ammonia gases after being heated and decomposed. The outer-layer pellet comprises a pore-forming agent and an outer-layer pelletizing material, and the pore-forming agent enables pores to be formed in the outer-layer pellet in the sintering process. The pore-forming agent such as ammonium bicarbonate in the multi-layer composite pellet is heated and decomposed to generate pores, a porous structure effectively delays the decomposition of the ammonia inhibitor such as urea and the release of NH3, so that the ammonia inhibitor is consistent with the NOX emission window period, the NOX emission is reduced, and the cooperative emission reduction of SO2, NOX and dioxin is achieved in a breakthrough manner.

Description

technical field [0001] The invention relates to the technical field of pollutant emission reduction in the sintering process, and more specifically relates to a multilayer composite pellet for suppressing SO2 and NOx in the sintering process. Background technique [0002] With the increasingly serious environmental problems and the gradual enhancement of people's awareness of environmental protection, the iron and steel industry, as a major source of pollutant emissions, has received more and more attention from the national environmental protection department. In 2019, my country's Ministry of Ecology and Environment and other five ministries and commissions jointly issued the "Opinions on Promoting the Implementation of Ultra-Low Emissions in the Iron and Steel Industry", requiring iron and steel enterprises across the country to significantly reduce pollutant emission levels, and set the emission standards for sintering / pelletizing process pollutants as particulate matter,...

AI Technical Summary

Problems solved by technology

[0006] The present invention aims at the technical problem of the addition of ammonia inhibitors in the sintering process and the relatively limited emission reduction efficiency of sintering flue gas pollutants in the prior art, and provides a multi-layer composite pellet for suppressing SO2 and NOx in the sintering process. It can form porous structure pellets containing ammonia inhibitors inside, which can properly delay the heating of ammonia inhibitors, make its decomposition time the same as the pollutant generation time in the sintering process, and improve emission reduction efficiency

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