last furnace coal injection is significant revolutionary measures ironmaking technology.Application of it, not only make the blast furnace coke rate greatly reduced, pig iron cost greatly decreased, may also be effective means of regulating furnace condition of thermal system, and also can enhance the reduction ability of the gas (hydrogen concentration in the gas increases), development of indirect reduction, also can improve the hearth working state, make the blast furnace stable line can also create conditions for blast furnace with high blast temperature, so the blast furnace coal injection technology for nearly a decade in the world and domestic large and medium blast furnace has been rapid development.
Domestic small blast furnace due to the limitations of technology, capital, knowledge and so on, the popularity of coal injection technology promotion is still very slow, in recent years, due to the ironmaking coke prices skyrocketing, coke by coal generation only caused a small blast furnace coal injection technology of the attention of the decision-makers.Small compared with the big blast furnace, blast furnace coal injection has obvious effect, more than the big blast furnace coal injection, for example, big blast furnace coal injection displacement ratio around 0.8, and small blast furnace can be up to 0.9 or so, even reached 1.0, after the small blast furnace coal injection of blast furnace is better than the increase of the pressure difference big blast furnace, namely after the small blast furnace coal injection for blast furnace permeability is greatly influenced by the blast furnace is small, the small blast furnace coal injection after thermal compensation needed for the small blast furnace greatly. So small easy to accept a larger blast furnace coal injection amount. Generally said, in the same level of up to 1000 degrees Celsius, about 100 cubic meters of blast furnace in the absence of oxygen enrichment and coal than iron and coal injection amount (t) of up to 120 kg. Now more than the small blast furnace ball type hot blast stove, air temperature is above 1100, thus can realize coal than the index of more than 120 kilograms.