Analysis of the coke distribution characteristics in hearth based on blast furnace dissection

Abstract

The occurrence state and consumption way of coke in blast furnace hearth are of great significance for efficient utilization of blast furnace fuel and low-carbon smelting. In this study, a 2200m3 blast furnace was dissected and core drilling was used to analyze the distribution characteristics of coke in the hearth systematically. It was found that the phases from the hot side of carbon brick to the hearth center were the hot metal channel, CaS agglomerate, slag‑iron-coke bonding phase, scattered coke along the radial direction. A large number of CaS were first found in the hearth with a radial width of 0.8 m. S and K elements were enriched at the interface between slag-coke and iron-coke, which hindered the carburization reaction and renewal mechanism of coke and was not conducive to its efficient utilization. In addition, the ore phase of the coke interface and interior alkali metal salt jointly led to its cracking. The distribution date and utilization ratio of coke in the hearth were clarified. The average coke size was 31.17 mm and the average voidage of the deadman was 40.99%. The mass loss of coke as reducing agent, heat source and carburizing agent during the decline in the furnace were 28.31%, 59.40% and 12.29% respectively.