Blast Furnace gas generation and usage Mar18

Blast Furnace gas generation and usage...

Blast Furnace gas generation and usage Blast furnace (BF) gas is a gaseous by product which is generated while producing hot metal (liquid iron) in a blast furnace. The operation of the blast furnace is controlled to produce hot metal of a specified quality and during this production BF gas comes out from the furnace top. During production of hot metal in a blast furnace, hot air blast is blown in the furnace through the tuyeres. The oxygen of the blast reacts with the coke. The gas produced by this reaction moves up the furnace shaft which has been charged with ores, fluxes and coke. After a number of chemical reactions and a travel of around 25-30m the BF gas comes out of the furnace as a heated, dust laden and lean combustible gas. Around 1500-1700 Cu m/ton of hot metal of BF gas is generated during the process. Though the purpose of partial combustion of carbon in a blast furnace is to remove the oxygen from the ore but the volume of gas generated in a blast furnace makes the blast furnace as a gas producer. The percentage of CO and CO2 in BF gas is directly related to the amount of carbon in the charged coke and amount of CO2 in the charged flux (Limestone and dolomite). The coke rate (The rate of carbon consumption) in the blast furnace depends mainly upon the type of the hot metal to be made, the chemical and the physical characteristics of the charged materials, the distribution of the materials in the furnace stack, the temperature and the oxygen enrichment of the hot air blast. The total amount of CO+CO2 gases by volume in the BF gas at the furnace top is around 40% of the...