Estudo para o uso de matérias-primas nacionais em misturas de carvões para obtenção de coque com características requeridas em altos-fornos de alta produtividade

Abstract

This study has the objective of exploring the possibility of utilizing alternative raw materials available in the country in the coal blends with high quality coals for producing high quality coke for the blast furnaces of Gerdau Acominas, Ouro Branco, Brasil.Characterization of the constituents of the blends (Low grade coal from Santa Catarina, Petroleum coke from REGAP Petrobras) has been carried out.Different blends were prepared with different percentages of the above with high grade coal were prepared and charged into the pilot furnace (carbolite furnace) of the Gerdau, Acominas and the coke produced was analyzed for different properties. The above pilot plant experiments were carried out for conventional cokemaking and also stamp charging of the coal blends.A mathematical model developed was taken as a reference for the quality of coke that would result in the prototype and this was used for predicting the coke properties on the basis of the pilot plant experiments.The results of the experiments show that it is possible to use noncoking coal of national origin up to 30 % in the coal blend with use of stamp charging to produce good quality coke for the blast furnaces, whereas in the conventional process only up to 10 % of the same can be used for maintaining the same quality.