Co-injection of Noncoking Coal and Natural Gas in Blast Furnace

摘要

The most radical method for saving coke in ironmaking is to inject gaseous, liquid and solid substitutes into the blast furnace (BF) hearth by means of tuyeres. Use of one or another type of auxiliary fuel depends on the ratio of their prices, their deposits and the peculiarity of the technology. This paper presents the basic theoretical proposals of a technology for the simultaneous injection by tuyeres of natural gas (NG) and pulverized coal (PC) with any ratio up to complete exception of one of them. A laboratory study had been carried out of the thermal decomposition and gasification of different types of coals. Determination has been made of the softening temperature and melting temperature of the ash of these coals. These temperatures play an important role in optimizing the tuyere assembly design, raceway processes and slag regimes. The factors which determine the oxidizing potential of the raceway have been established.