Estudo da redução do consumo de fundentes no processo de dessulfuração em planta KR.

Abstract

Sulfur will always be present in steel since it is present in the raw materials used in the manufacturing process. In addition, with the growth in the mining area, these inputs are increasingly poor, that is, with a greater amount of contaminants and, consequently, with a higher percentage of sulfur contained in them. For this reason, desulphurisation becomes extremely necessary in the steelmaking process. The treatment of the desulphurisation of the pig iron in the Kanbara reactor (KR) basically consists of the addition of desulfurants in the mechanically stirred bath. The mechanical agitation increases the contact of the liquid metal with these agents, favoring the reactions and improving the efficiency of the process. The desulfurizing agents are added and, by means of chemical reactions, bind to the sulfur, removing it from the bath. Considering that the only inputs used in this process are the fluxes, the reduction of their consumption causes a strong impact on the costs related to the desulphurisation of the pig iron. The PDCA methodology (Plan, Do, Check and Act) was applied and, following the analysis of an opportunity to improve the addition of desulfurants in KR, the tests were started. After the tests, it was possible to observe the reduction of 11% in lime consumption and 13% in fluorite consumption. In order to predict sulfur content after desulphurisation, tools such as linear regression and neural networks were used. The expected results showed good coefficients if we take into account the statistics of industrial forecasts.