某贫磁铁矿选矿厂一段磨矿分级工艺考查与优化建议  

Process Investigation and Optimization Suggestion on the First Stage Grinding and Classification of a Lean Magnetite Concentrator

作　　者：刘哲 李丽匣[1] 周明亮 李楠[1] 刘飞飞 卢冀伟[1] 张强 张俊飞 LIU Zhe;LI Lixia;ZHOU Mingliang;LI Nan;LIU Feifei;LU Jiwei;ZHANG Qiang;ZHANG Junfei(School of Resources and Civil Engineering,Northeastern University;Liaoning Wuhuan Special Materials and Intelligent Equipment Industry Technology Research Institute Co.,Ltd.)

机构地区：[1]东北大学资源与土木工程学院 [2]辽宁五寰特种材料与智能装备产业技术研究院有限公司

出　　处：《现代矿业》2023年第10期238-241,共4页Modern Mining

基　　金：国家自然科学基金项目(编号:52174243)。

摘　　要：某贫磁铁矿选矿厂的矿石矿物组成复杂、嵌布粒度细、分布不均、可磨性差,属难处理矿石,现场一段磨矿分级系统工作效率低,产品指标未能达到原设计值,为查明原因并加以优化改造进行了工艺流程考查。结果表明,由球磨机与双螺旋分级机组成的一段闭路磨矿系统磨矿浓度为80.73%,介质充填率为45%,负荷率为86.04%,返砂比为47.83%,分级量效率为85.93%,分级质效率为25.75%,磨矿浓度与介质填充率均在合适范围内,但返砂比、分级质效率过低,螺旋分级机型号偏大,导致返砂比低,返砂量小,分级效果差,较多粗颗粒进入到溢流中,导致了球磨机的处理量和负荷率低;分级质效率低,溢流中混杂大量未单体解离的粗颗粒影响了一段磁选效果,导致一段磁选尾矿中有用矿物流失较严重。根据考查结果,建议将螺旋分级机更换为水力旋流器,以提高分级效率,进而增强一段磨矿能力,提高磨矿效率和选矿厂的生产能力;将一段磁选机更换为大包角、选别带长、选别效率高的磁选机,以提高磁铁矿的回收率,降低金属损失率。The ore of a lean magnetite ore dressing plant is a refractory ore with complex mineral composition,fine disseminated particle size,uneven distribution and poor grindability.The working efficiency of the first-stage grinding and classification system on site is low,and the product index fails to reach the original design value.In order to find out the reason and optimize the process,the process flow was investigated.The investigation showed that the first-stage closed-circuit grinding system,consisting of a ball mill and a double spiral classifier,had the grinding concentration of 80.73%,the medium filling rate of 45%,the loading rate of 86.04%,the sand return ratio of 47.83%,the classification quantity efficiency of 85.93%,and the classification quality efficiency of 25.75%.The grinding concentration and medium filling rate were within the appropriate range,but the sand return ratio and classification quality efficiency were too low,and the spiral classifier model was too large,resulting in low sand return ratio,small sand return volume,poor classification effect.More coarse particles entered the overflow,as a result,the processing capacity and load rate of the ball mill was low.The classification quality efficiency was low,and a large number of coarse particles without monomer dissociation were mixed in the overflow,which affected the effect of the first-stage magnetic separation,resulting in serious loss of useful minerals in the tailings of the first-stage magnetic separation.According to the test results,it is suggested that the spiral classifier should be replaced by a hydrocyclone to improve the classification efficiency,thereby enhancing the first-stage grinding capacity,improving the grinding efficiency and the production capacity of the concentrator.In order to improve the recovery rate of magnetite and reduce the metal loss rate,the first-stage magnetic separator should be replaced by a magnetic separator with large wrap angle,long separation band and high separation efficiency.

关 键 词：磁铁矿石 流程考查 磨矿分级 分级效率 处理能力 

分 类 号：TD4[矿业工程—矿山机电]