Research On Injection Performance Of CDQ Ash Injection Into BF

In recent years, with the continuous expansion of the scale of blast furnace (BF) ironmaking and the pig iron production continues to increase, therefore, coke’s requirement isgrowing. Because of the necessity of coke for BF iron making and the shortage of coking coal,producers try to use other sources of fuels instead of coke. Various injection fuels throughraceway have been developed to partially replace coke, these injection fuels contain oil,pulverized coal and natural gas, but, pulverized coal injection (PCI) is the most effectivetechnology to reduce BF coke consumption. PCI has been practiced world wide and has becomea well-established technology over the last decade.BF coal injection rate continues to increase, while suitable for BF injection of anthraciteresources are limited. In recent years, the coke dry quenching (CDQ) technology has beenwidely used at home and abroad, a large amount of ash is produced during the process of CDQ.The chemical composition of CDQ ash and anthracite are very similar, and the particle sizecomposition of CDQ ash is also very close with the BF pulverized coal. Therefore, thisexperiment will explore the feasibility of the cheap CDQ ash be used to replace part of anthraciteas BF pulverized coal. The CDQ ash used to blast furnace injection can not only save anthraciteresources, reduce iron making costs, but also can reduce the emission of pollutants.Because ofthe CDQ ash obvious economic value and environmental advantages, it is very necessary toresearch the CDQ ash’s injection performance of pulverized coal.In this research, seven mixed coal programs are drawn up on the basis of four kinds ofsingle coal which are provided by one large steel enterprise. According to the BF injectionpractice of the steel enterprise found that influence the effect of injection performance ispulverized coal reactivity and combustibility, while the grindability of coal is the main factoraffecting the cost of milling. Therefore, the grindability, reactivity and combustibility of fourkinds of single coal and seven mixed coal has been studied in this research. Finally, through theestablishment of mathematical model to select the best mixed coal program.The experimentalresults show that the CDQ ash compared with the remaining three kinds of single coal, itsgrindability, reactivity and combustibility is worse than the other three. The injectionperformance of pulverized coal will be little effected when the appropriate proportion of CDQash into pulverized coal. The preliminary result indicate that the ratio of CDQ ash under theconditions of less than5%, CDQ ash injection into BF is feasible.