江西某铜矿大型球磨机介质制度优化试验研究

Experimental Study on Optimizing the Media System of Large-scale Ball Mill in a Copper Mine in Jiangxi Province

针对江西某铜矿选厂大型球磨机磨矿产品质量差、处理量低、运转率低和能耗高等问题,在测定矿石力学性质的基础上,采用控制变量法,通过对比多组实验室试验方案的磨矿效果,最终确定球磨机的最佳介质制度为φ60∶φ50∶φ40∶φ30=30∶25∶30∶15。试验结果表明:推荐钢球方案较现场方案过粗粒级级别产率降低了1.21个百分点,中间易选粒级级别产率提高了2.53个百分点,过粉碎粒级级别产率减少了0.32个百分点;较钢段方案过粗粒级、磨矿细度-0.074 mm占比和中间易选级别产率分别提高了4.58个百分点、1.48个百分点和3.25个百分点,对比工业试验前后矿石月处理量提高了13242 t,运转率提高了2.18个百分点,月功率降低了173 kW。研究表明:优化磨矿介质制度不仅可以提高磨矿产品质量,而且对节能降耗具有重要的促进意义,有助于提升公司核心技术水平,对同类型矿山具有借鉴意义。

In order to improve the problems of unreasonable particle size composition,low processing capacity,low transfer rate and high energy consumption of large-scale ball mill grinding products,achieving the purpose of improving the quality of grinding products and optimizing the beneficiation index of the beneficiation plant in a copper mine in Jiangxi,in this paper,the test is performed according to the following steps.Firstly,the main mechanical properties of the ore were determined,including bulk density,elastic modulus,and Poisson’s ratio.Secondly,a laboratory grinding comparison test was carried out in a D×L=240 mm×300 mm mill,by comparing the grinding effects of the five grinding schemes of the recommended scheme,the plant scheme,the larger scheme,the smaller scheme,and the steel section scheme,the working media system of the mill media with the best ore matching of the concentrator was finally determined asφ60∶φ50∶φ40∶φ30=30∶25∶30∶15.Summarizing the ore mechanical property test results and laboratory grinding test results,we can conclude that:The ore mechanical property test results show that the average ore bulk density is 2.78 g/cm3,the average hardness is 7.9,the average elastic modulus is 3.11×104 MPa,and Poisson’s ratio with average value of 0.25.The overall properties of the ore are media hardness but high toughness.During the ore grinding process,the number of grinding times per unit time should be strengthened.The results of laboratory grinding show that the recommended scheme has a reduction of 1.21 percentage points in the coarse grade(+0.200 mm)and 0.32 percentage points in the over-comminuted grade(-0.010 mm)and the intermedia easily selectable grade(-0.200+0.010 mm)grain content increased by 2.53 percentage points compared with the current plant scheme;Recommended scheme has a better grinding effect compared with steel section scheme,although the overcomminuted grade(-0.010 mm)grain of recommended scheme is 2.75 percentage points higher,the coarse grade(+0.200 mm)grain grade content,grinding fineness(-0.074 mm)grain grade content and intermediate easily selectable grade(-0.200+0.010 mm)grain grade content have increased respectively,they increased by 4.58 percentage points,1.48 percentage points and 3.25 percentage points.Compared with data before and afterthe industrial test,the monthly processing capacity was increased by 13242 t,the transfer rate of the mill was increased by 2.18 percentage points and the monthly power consumption was reduced by 173 kW.It shows that optimizing the grinding media system can not only improve the quality of the grinding products to a certain extent,but also have an important promotion significance for energy saving and consumption reduction,significantly improve the company’s core technical level and have reference significance for the same type of mine.