Producing high coke strength after reactivity in stamp charged coke making

Abstract

In recent years, blast furnaces of larger volume have come into use and the requirements for coke strength have become increasingly severe. The dissections of Nippon Steel Corporation blast furnaces have revealed considerable changes in coke properties in the lower furnace regions. With increased use of Pulverized Coal Injection, improved hot coke strength will be required for efficient and consistent performance in the furnace. The present study revealed that the CSR of coke produced by stamped charged coke making process is mainly influenced by the properties of coal like petrography, coal ash chemistry and rheology. In stamp charging condition, to produce coke with high CSR value, it is necessary to select coals with appropriate ash chemistry, petrographic properties and rheological properties must be maintained. The coal blends which improve the coke CSR beyond a certain limit generate high oven wall pressure. The investigation results show that for producing greater than seventy CSR, coal basicity, fluidity temperature range and inertinite value must be less than 0.2, minimum 90°C and 32 volume % respectively.