Pulverized coal injection in a blast furnace May10

Pulverized coal injection in a blast furnace...

Pulverized coal injection in a blast furnace Pulverized Coal Injection (PCI) is a process that involves injecting large volumes of fine coal particles into the raceway of a blast furnace (BF). This provides not only a supplemental carbon source but also speeds up the production of liquid iron besides reducing the need for metallurgical coke for reactions in the blast furnace. The desire to move away from the production of the metallurgical coke with its inherent environmental problems has motivated the use of pulverized coal injection in blast furnace. History Pulverized coal injection was developed in 19th century, but was not implemented for industrial use. In early sixties of the last century PCI was successfully implemented in AK Steel of USA and Shougang in China. Though trials in several countries at that time had proved that the technology for pneumatic transport and injection of coal were available, but the economics and relative ease of the process was such that oil and natural gas injection became more popular. During energy crises of seventies people started showing interest in the process of PCI. This process developed very fast during 1980s and in the second half of the 1980s there were successful practices of coal injections at rates ranging from 180 Kg/tHM to 200 Kg/tHM. In nineties PCI technologies became mature. But the real shift to PCI has taken place only when the cost of metallurgical coke started rising due to the increased global demand. Concept and the process of coal injection The PCI technology is based on the simple concept of carrying the finely ground (pulverized) dried coal by a conveying gas (normally nitrogen) to the blast furnace where it is distributed to different tuyeres and injected through a lance in the blow pipe. In the...