DOC《本溪市某选矿厂三段磨矿工艺改造》

本溪市某选矿厂三段磨矿工艺改造 徐彪 李肖 陈煊年 (本钢集团有限公司矿山技术研发所) (地址:辽宁省本溪市南芬区露天矿矿办 邮编11700) 摘要 本溪市某选矿厂生产一直采用两段磨矿工艺,由于矿石性质的变化和生产任务加重,选矿厂生产指标变化浮动大,因此进行了三段磨矿工艺改造.

通过三段磨矿工艺改造,选厂生产能力提高7.63t/h・台,金属回收率提高7.78%,选别效率提高9.71%,选比降低0.28t/t,精矿品位稳定在66.60%以上,尾矿品位由原来的17.38%降低到14.00%. 关键词 三段磨矿 精矿品位 尾矿品位 金属回收率 选比 Improvement of three stage grinding process of a concentrator in Benxi XuBiao LiXiao ChenXuanNian (Benxi Steel Group Corporation Mine technology research and Development Institute) (Liaoning province benxi city Nanfen district

117000 China) Abstract: The two stage grinding process had been adopted in a concentrator in Benxi. Because of the change of ore properties and the increase of productive tasks, the production-indexes of concentrator had changed greatly. The three stage grinding process had been improved in the concentrator. The three stage grinding process transformation, raised production capacity of mill 7.63t/h・ unit, the metal recovery rate is increased by 7.78%, the separation efficiency increased by 9.71%, the concentration ratio reduced 0.28t/t, the concentrate grade is stabilized at more than 66.60%, the tailings grade reduced from 17.38% to 14%. Keyword: three stage grinding process;

concentrate grade;

tailings grade;

metal recovery rate;

concentration ratio 本溪某选矿厂年处理矿石1200万吨,生产铁精矿420万吨,生产工艺为两段磨矿全磁选工艺,近年来由于矿石性质变化和生产任务加重,两段磨矿全磁选工艺不能适应现生产矿石,铁精矿质量不稳定,尾矿品位高,金属回收率低,因此进行三段磨矿工艺改造,优化工艺流程,适应矿石性质变化,满足生产要求[1-2]. 1改造方案 1.1三段磨矿工艺改造依据 通过对该选矿厂两段磨矿工艺进行流程考察和矿石性质分析,三段磨矿改造工艺合理、技术可行. 第一,矿石难磨,结晶粒度细,磁铁矿呈自形晶和半自形晶粒状结构;

假象赤铁矿呈它形晶状结构,假象赤铁矿和磁铁矿之间常形成交代结构.磁铁矿和假象赤铁矿被石英晶体包裹形成包含结构.有用矿物粒度分布:最小粒度12.13μm,最大粒度581.44μm,平均粒度109.86μm. 第二,现场两段磨矿工艺尾矿品位18%,对尾矿进行再磨磁选回收试验,铁精矿达到品位60.84%,因此部分磁铁矿由于没有达到单体解离直接影响最终的选别指标[3-4]. 第三,现场两段磨矿工艺中磁选柱中矿和高频细筛筛上产品返回二段磨矿处理,增加二段磨矿负担,同时由于磨矿细度要求不一样,二段磨矿不能高效的使这部分产品单体解离,产生局部循环,导致金属损失. 1.2三段磨矿工艺改造方案 三段磨矿工艺改造以现有两段磨矿工艺为基础,建设一个三磨车间,处理磁选柱中矿、高频细筛筛上产品.三段磨矿工艺建设规模,100万吨磨选能力.主要工艺设备:Ф4.3*8.5溢流型球磨机1台,FX-250*22旋流器组1组,CS-3000永磁脱水槽4台,1230永磁磁选机6台[5-7]. 2改造前后工艺流程对比 对该选矿厂三段磨选工艺改造运行前后的工艺流程进行全流程考察.分别得到运行前后数质量流程图: 表1 三段磨矿工艺运行前后生产指标对比 Table