东鞍山混磁精矿搅拌磨与球磨对比试验

Optimization Test of Stirred Mill for Mixed Magnetic Concentrate from Donganshan

鞍钢东鞍山烧结厂原矿主要以细粒嵌布的赤铁矿和磁铁矿为主,为解决现场球磨机效率低、有用矿物单体解离度低等问题,进行了陶瓷球搅拌磨、球磨工艺的优化和对比试验。试验结果表明,搅拌磨适宜条件为充填率80%、料球比0.9、磨矿质量浓度60%、介质尺寸6 mm、搅拌器转速650 r/min;球磨适宜条件为介质质量配比为m(32 mm):m(25 mm):m(19 mm)为5:3:2、充填率40%、料球比1.0、磨矿质量浓度70%。此时搅拌磨机磨矿效果更好,-0.038 mm比生产率达3636.20 kg/(m^(3)·h),磨矿效率达71.93 kg/(kW·h)。相同细度样品分析表明,搅拌磨产品中过细和过粗粒级含量均相对较少,有用矿物单体解离度比球磨高4.5%~8%。反浮选试验表明,搅拌磨可将精矿铁品位和回收率分别提高0.94和2.99个百分点。因此,搅拌磨机比球磨机具有更好的磨矿效果和浮选指标。

The raw ore is mainly fine disseminated hematite and magnetite in Donganshan Sintering Plant.The field problems are low efficiency of ball milling and low monomer dissociation etc.In this research,the process optimization and comparison of magnetic concentrate ball milling and ceramic ball stirring grinding were carried out.The results show that the optimum conditions of stirring mill are as follows:filling rate of 80%,material ball ratio of 0.9,grinding concentration of 60%,medium size of 6 mm and agitator speed of 650 r/min.For ball milling,the optimum conditions are as follows:the medium ratio of 32 mm:25 mm:19 mm of 5:3:2,filling rate of 40%,material ball ratio of 1.0,grinding concentration of 70%.And the grinding effect of stirring mill is better.The specific productivity of-0.038 mm is 3636.20 kg/(m^(3)·h),and the grinding efficiency is 71.93 kg/(kW·h).The analysis of samples with the same fineness shows that the content of superfine and coarser particles is relatively small in stirred mill products,and the dissociation degree of useful mineral monomer is 4.5%~8%higher than that of ball milling.The reverse flotation test shows that the iron grade and recovery rate of concentrate can be increased by 0.94%and 2.99%,respectively.Therefore,agitation mill has better grinding effect and flotation index than ball mill.