重选—筛分工艺分选高炉除尘灰试验与实践

Research and Application of Gravity Separation-Screening Process in Handling the Blast Furnace Dust

某高炉除尘灰-0.074 mm占70.30%,有价成分为铁、炭、锌,铁在-0.074 mm粒级有明显的富集现象;锌主要分布于-0.065 mm粒级;试样粒度越粗炭分布率越高。试验对该试样进行了选矿试验研究,结果表明,在磨矿细度为-200目占85%的情况下,采用螺旋溜槽粗选、环形摇床精选、螺旋溜槽粗选尾矿筛分工艺处理试样,可获得铁品位达57.40%、回收率达47.08%的铁精粉,固定碳含量达67.18%、回收率达63.09%的炭精粉,以及锌含量为6.04%、回收率达74.47%富锌料。以试验流程为基础建设的生产工艺系统处理铁含量为31.50%、碳含量为25.20%、锌含量为2.46%的高炉除尘灰,在磨矿细度为-200目占85%的情况下,获得的铁精粉铁品位达55.30%、回收率达53.72%;炭精粉固定碳含量达67.81%、回收率达60.76%;富锌料锌含量为5.81%、回收率达74.18%。铁精粉、炭精粉和富锌料品质均满足返厂或作为产品销售的要求。该工艺是高炉除尘灰处理的低成本、高效率工艺,具有较高的推广、应用价值。

A blast furnace dust with particle size of 0.074 mm or below accounts for 70.30%,and the valuable compo-nents of iron,carbon,zinc,iron in the 0.074 mm grain size have obvious enrichment phenomenon;Zinc is mainly distributed inthe 0.065 mm grain size or below;The rougher the particle size is,the higher the carbon distribution is.Mineral processingtests on the sample were carried out,and the results indicated that under grinding fineness of 85% passing 200 mesh,iron con-centrate with iron grade of 57.40% and recovery of 47.08%,the carbon powder with grade of 67.18% and recovery of 63.09%,and the zinc-enriched material with zinc grade of 6.04% and recovery of 74.47% were obtained by adopting theprocess of spiral chute for roughing,annular tabling for rough concentrate,spiral chute for screening rough tailings.On the basisof the test process,the production process was adopted to handle the blast furnace dust with iron content of 31.50%,carboncontent of 31.50% and zinc content of 2.46%.In the case of grinding fineness of 85% passing 200 mesh,iron concentratewith iron grade of 55.30%,and recovery rate of 53.72%,the carbon powder with grade of 67.81%,and recovery rate of60.76%,the zinc-enriched material with zinc grade of 5.81% and recovery of 74.18% were obtained separately.The quality ofiron concentrate,carbon powder and zinc-enriched material all meet the requirements of returning to the factory or is used asproduct sales.This process has features of low cost and high efficiency in handling the blast furnace dust with a promotion andapplication value.