江西某铜矿磨矿对比试验及应用研究

Comparison Test and Application Study on Grinding of a Copper Mine in Jiangxi Province

针对江西某选厂铜矿石磨矿产品粒度组成差、铜回收率低及磨矿介质消耗量大的问题,以矿石性质为依据,通过实验室磨矿对比试验提出工业化应用的最佳磨矿介质尺寸及配比方案,从而达到改善磨矿效果的目的。实验室磨矿对比试验得出处理矿石的最优初装球方案为?70∶?50∶?40∶?30=20∶30∶20∶30。工业试验期间,从现场7#和8#球磨机溢流中取得矿样,在实验室进行浮选对比试验。工业试验结果表明:应用推荐和2.13%,+0.2 mm百分含量减少了3.14%,中间易选级别-0.2+0.038 mm百分含量提高了2.68%,铜回收率提高了3.70%,球耗降低了0.032 kg/t,为提高铜的浮选回收率创造了有利条件,同时对提高磨矿作业质量具有一定的指导意义。

The properties of copper ores in a copper concentrator in Jiangxi Province have changed greatly since August 2016,which resulting in obvious differences in particle size composition of grinding products,large consumption of grinding media and reduction of copper recovery rate in the flotation process.Starting with the size and proportion of grinding media,through the determination of ore properties,comparative grinding tests and industrial application work,the purpose of improving the quality of grinding products and copper sorting indexes and reducing the steel ball consumption can be achieved. The mechanical properties of 16 ore blocks with specifications greater than 200 mm were determined on a press of model DE50A.According to the measurement of rock mechanical properties,the average values of Pushi hardness coefficient f and Poisson’s ratio of the porphyry copper ore in this concentrator are only 5 and 0.155,respectively,belonging to soft and brittle ores. The comparison test of copper ore grinding in the concentrator was carried out in a 450 mm× 450 mm discontinuous ball mill in the laboratory.According to the mechanical properties of the ore and the grinding conditions in the field,the maximum grinding ball diameter was calculated to be 70 mm,and four groups of grinding test schemes were formulated and the grinding test was carried out with the steel ball ratio of each scheme. According to the calculation of grinding medium size and ratio and the laboratory grinding comparison test,the optimal grinding medium size and ratio of 3.2 m× 3.1 m lattice ball mill in concentrator is Ф70∶Ф50∶Ф40∶Ф30= 20∶30∶20∶30.The grain size uniformity of the grinding products in this scheme is the best,the coarse grade yield including +0.2 mm grain size is the lowest,while the intermediate easy grade,-0.2 +0.038 mm grain size yield is the highest,reaching 66.78%,while the -0.038 mm grain size content is lower. During the industrial test, ore samples were obtained from the overflow of the 7# and 8# mills on site,and flotation comparison tests were carried out in the laboratory XFD-0.5 mini flotation machine.The industrial test results show that the content of -0.038 mm and -0.074 mm in grinding products increased by 0.47%,2.13%,and the content of + 0.2 mm decreased by 3.14% after using the recommended medium scheme. The content of -0.2 + 0.038 mm in the intermediate easy-to-select grade increased by 2.68%,the copper recovery rate increased by 3.70%,and the unit ball consumption decreased by 0.032 kg/t. The aim of improving the grain size composition of grinding products,improving the sorting index of copper and reducing the unit consumption of medium in the copper ore processing operation of the concentrator is achieved,and it has certain guiding significance for improving the quality of grinding operations.