基于正交设计和离散元法的半自磨机筒体衬板改型及工业应用

Modification and Industrial Application of Liners of Semi−autogenous Grinding Mill Based on Orthogonal Design and Discrete Element Method

针对新疆某选厂Φ5.5 m×1.8 m半自磨机筒体衬板易磨损、断裂等问题,首先基于正交试验确定其筒体衬板的最优结构参数,其次运用离散元法模拟现场半自磨机的运行过程,对比研究在不同衬板结构参数下(提升条高度、宽度与面角)半自磨机内颗粒运动及内部碰撞能量的变化规律,最后通过工业试验验证优化方案的可行性。研究结果表明:适宜的提升条参数组合可有效优化磨机内颗粒的运动状态,增加钢球—矿石、矿石—矿石的有用碰撞,减少因无用碰撞引起的衬板或磨矿介质的损耗,进而改善半自磨机的运行参数。经正交试验确定最优的衬板提升条参数组合为高度190 mm、宽度140 mm和面角60°。由工业试验验证,优化后的衬板使用寿命、磨机运转率与台效较优化前分别提高了51 d、16.36百分点、15.55 t/h,磨机电耗较优化前降低了6.07 kW·h/t。试验结果证明了正交设计法和离散元法的联合应用在半自磨机筒体衬板形状优化过程的可靠性及优越性。

In order to solve the problem that the liners ofΦ5.5 m×1.8 m SAG mill were easy to wear and fracture in a concentrator in Xinjiang.Firstly,the optimum structural parameters of cylinder liners were determined by the orthogonal test.Secondly,The discrete element method(DEM)was used to simulate the real operation of SAG mills.Based on the different structural parameters of cylinder liners(height,width and angle of lifter bars),the motion of particles and the change of collision energy in SAG mills were studied.Finally,the feasibility of the optimization scheme was verified by industrial tests.The results showed that a suitable parameters of the liners can effectively optimize the motion of particles in the mill,increase the effective collision of ball to ore and ore to ore,reduce the wear of liners or grinding media caused by invalid collision,and thus improve the operating parameters of the semi-autogenous mill.The optimum parameters of the lifter bars were determined by orthogonal experiment to be 190 mm in height,140 mm in width and 60°in angle.The optimum parameters of liners were used to carry out industrial tests.The results showed that the optimized liner service life,mill operation rate and efficiency were increased by 51 days,16.36%and 15.55 t/h,and the mill power consumption decreased by 6.07 kW·h/t.The results verified the reliability and superiority of the discrete element method and the orthogonal design method in the modification of the cylinder liners.