Blast furnace gas is a by-product gas produced in the process of iron making process. The main raw materials for the production are iron ore (ore or ore), limestone, accelerant, and coke is the main fuel. During the coke combustion process, it starts from the air surplus state and gradually become the combustion state of the air, finally it produces a blast furnace gas, which also can be referred to as BFG gas or B gas. One tons of cast iron can generate 2000 m3 combustible gas and its main ingredient is CO, which is a low calorific value gas that can be used alone for low calorific value gas or mixed with coke oven gas (M).
Blast furnace gas properties:
1. Colorless, tasteless, highly toxic, flammable and explosive
2. Calorific value: 800 - 950 kcal / m3
3. Specific gravity: 1.295 kg/m3
4. Fire point: 700℃
5. Combustion temperature: 1400℃
6. Explosion range: 40 ~ 70%
7. Air need for combustion: 0.83 ~ 0.85 m3 m3/
Converter gas refers to that oxygen extends into the proper position to molten iron from the top of the stove mouth through the oxygen lance, during the converter steelmaking process. At this time, iron oxides, especially the FeO and carbon compounds in molten iron, produce contains large amounts of carbon monoxide gas. The by produced combustible gas is the converter gas.
The heat value of converter gas is lower than that of coke oven gas, but it is higher than that of blast furnace gas. Gases contain a great content of CO and about 15% CO2, nitrogen and a small amounts of oxygen and oxides, and the higher amount of dust. So it is usually used as a exhaust discharged or burned. the nature is same with the blast furnace gas. For this reason, the use of the converter gas is usually mixed with other high calorific value of fuel in the rotary kiln of the active lime calcination.
Converter gas is a toxic, flammable, colorless and tasteless, gas calorific value of 1700 kcal - 2000 /m3 gas after purification.
By practice, the blast furnace gas and converter gas are suitable for active lime calcination.
