Comprehensive Utilization Of Panzhihua Iron And Steel Blast Furnace Gas Mud

The results of zinc equilibrium measurement of No. 1 and 2 blast furnaces of Pan Steel showed that the duties of materials of blast furnaces were amounted to 830g/tFe, which were higher than the most ones of other large and medium internal blast furnaces. The proportion of sinter was the biggest item of zinc incomes and pellet was the second big one. The proportions of sinter and pellet of the two BFs were respectively 97.13% and 97.28%. Blast furnace sludge was the biggest item of zinc outcomes and amounted to 88. 56% and 93.04% in zinc outcomes respectively. With blast furnace dust, the proportions of the two items of the two BFs were respectively 98.77% and 98.29%. So we can see that the most of zinc were discharged with gas from the top of blast furnaces. The results of sampling from Fan Steel showed that the content of iron in sludge was about 30% - 35%, carbon 16% and zinc 3% - 7%. Because of the high contents of iron and carbon, sludge should be reclaimed. But the content of zinc was so high that if sludge were blended in sinter and pellet directly, zinc would entered into blast furnace again, which would be detrimental to production and blast furnace. A mass of zinc were founded at inside of large bell and gas up-take when blast furnace were in down time, and liner erosion by the permeation of zinc were also founded. The harm of zinc to blast furnaces of Pan Steel were emerged gradually. If sludge were discarded, it not only wasted large amount of resources but polluted environments severely. So sludge of Pan Steel should be polyreclaimed and iron, carbon and zinc could be reuntilized again.Sludge of Pan Steel were firstly disposed by mineral seperation and then the mill tailings of sludge were reduced by pyrometallurgy process to reclaim zinc, and iron in the slag tails were reclaimed by magnetic seperation. The results of dezincing experiments of sludge showed that both zinc evaporation degrees and iorn metallization degrees increased with reduction temperature and time, but reduction temperature was the decisive factor. The results of comparative experiments between sludge pellet and powder showed that there were not difference between them on the same conditions. The enhancement of the basicities of sludge were in favor of the increasement of zinc evaporation degrees and iron metallization degrees on the sameexperiment conditions, but the effects were not remarkable. The influences of extra carbon of sludge on zinc evaporation degrees and iron metallization were not obvious. The increasement of extra carbon in sludge could improved the soft performance remarkably and reduced cementing of materials. After the slag tails were dealed with by magnetic seperation, iron contents of mineral concentrates could exceeded 65% and iron recovery ratios could exceeded 90%. According to the results of these experiments, the optimum process parameters should be that the mixed materials are made up of sludge fines and coal fines, limestone fines are not needed, reduction temperature of 1150 - 1200℃, reduction time of 20 - 30min. On this condition, zinc evaporation degree can exceeded 95% and iron metallization degree 90%, which meet the request of reclaiming zinc and iron from sludge absolutely. The slag tails are then dealed with magnetic seperation.