Research on production technology of alkaline pelletizing and application of high proportion in blast furnace

High proportion of blast furnace pellet smelting is an inevitable trend of low-carbon iron making. In order to build a new generation of process steel mills with "green, intelligent and brand", HBIS Group Tangsteel New District independently designed and built two belt roasting machines with the largest output of 624 m² in China to meet the demand for high-proportion pellet smelting in large blast furnaces. Tangsteel has carried out a series of research works on the production of high-quality alkaline pellets. Through technical measures such as fine powder quality improvement, optimization of ore allocation, improvement of pelletizing and optimization of roasting, the technical bottleneck problem of poor low temperature reducing pulverization performance of alkaline pellets has been successfully solved, and the stable production of alkaline pellets with quality and quantity has been realized. On this basis, the three 3 000 m³ blast furnaces of Tangsteel successfully smelt 40% to 60% high proportion pellets by using basic pellets. Through improving the quality of raw fuel, activating the furnace cylinder, controlling the reasonable operation of the furnace type, and adopting comprehensive smelting measures such as high top pressure, large air volume, high oxygen enrichment and low furnace temperature, various technical indicators of the blast furnace have steadily improved and achieved good smelting results.