改善磨矿效果提高镍精矿指标的研究

Improving Indicator of Nickel Concentrate by Enhancing Effect of Grinding

介绍了一种在不改变碎磨及浮选流程的前提下提高镍精矿浮选指标的方法。从矿石的力学性质出发,按照精确化装补球方法精确计算出二段磨机的初装球球径和球比,确定了推荐初装球方案(质量比)Φ40∶Φ30∶Φ20=40∶40∶20,然后根据二段细磨的要求及质量相当的原则用铸铁段代替钢球,最终确定了D(直径)×L(长度)(质量比)35×40∶30×35∶25×30=30∶30∶40为磨机初装介质推荐方案,并设计了其他几种磨矿方案与之进行对比。实验室研究结果表明:钢球的直径和配比经过优化之后,其磨机磨矿产品粒度组成趋于合理,过粗粒级及过粉碎粒级产率明显降低,中间易选级别显著提高,主要原因是磨矿产品的选择性解离增强。通过工业化试验进一步验证,验证结果表明:运用新的磨矿介质制度之后,磨矿细度平均提高了8.68%。试验后期,镍回收率提高了2.53%,铜回收率提高了4.99%,镍精矿品位提高了0.36%,铜精矿品位提高了3.65%,精矿氧化镁含量降低了9.16%,达到了提高镍精矿回收率、品位、降低镍精矿中氧化镁含量的预期效果。

The paper introduced a method of improving the flotation indexes of nickel concentrate on the premise of that the grinding and flotation process remained the same. Based on the mechanical property of ore,the accurate ball-load-addition method was adopted to calculate the optimum ball diameter of initial installation ball and ball ratio accurately at the second stage grinding and eventually determined the initial installation scheme of Φ40 ∶ Φ30 ∶ Φ20 = 40 ∶ 40 ∶ 20. According to the requirement of fine grinding at the second stage and the mass equivalent principle,steel balls were replaced by cylpebs and the medium charge scheme was eventually determined as D（ diameter） × L（ length） 35 × 40∶ 30 × 35∶ 25 × 30 = 30∶ 30∶ 40. In addition,some other schemes were designed to make a contrast with the method. The results proved that the particle-size composition of grinding product tended to be more reasonable after optimizing the ball diameter and the proportion. That was to say,the over-coarse and over-ground proportions decreased significantly,and the easy selection grade increased apparently for the enhanced selective disintegration. The further commercial-scale manufacture verified that the grinding fineness increased by 8. 68% after using new grinding medium. At the end of the experiment,expected results could be obtained that the nickel recovery increased by 2. 53%,the copper recovery increased by 4. 99%,the nickel concentrate grade increased by 0. 36%and the copper concentrate grade increased by 3. 65%,and the amount of Mg O in the nickel concentrate decreased by 9. 16%.