Avaliação da influência do tempo de estocagem em pilhas na qualidade de carvões metalúrgicos

Abstract

The quality of coal used in the mix for production of coke used in blast furnaces is important for obtainment of a coke within characteristics demanded. Maintain the coke quality without great variations will enable a stable operation of the blast furnace.The objectives of this study were to evaluate the variations in metallurgical coals used for production of coke for blast furnace during stockpiling and to evaluate the influence of origin, volatile matter and climate factors on the characteristics of coals duringstockpiling .The experimental program for this study involved the formation of little coal piles from different origins and characteristics and their periodical sampling for determination of the main quality parameters and its variation during the time of stocking.The results of the sampling and statistical analyses performed showed that changes occur in coal quality parameters during the period of storage in coalyards. Thesechanges differ in intensity according to the type of coal analyzed. So the final consumers of the metallurgical coal must have a special control on the period of storage to avoid variations in the quality of coke and its consequences towards the entire process of manufacturing steel.The development of laboratory methods for the control of oxidation can be an important tool in the quality control of the metallurgical coal. Tests should be performed in order to verify what methods provide more reliable results and are easy to implement.