大型半自磨机磨矿性能仿真及参数优化

发布时间：2018-11-07 08:13

【摘要】：半自磨机是选矿作业的主要设备之一,其“大型化”已成为磨矿设备的主要发展趋势。针对大型半自磨机实际生产过程中存在的较高功耗、钢耗问题,本文基于国家自然基金项目(NO.51265020)“多场耦合条件下中空轴式重载静压轴承设计理论与方法”,运用离散元方法,对大型半自磨机的磨矿性能进行了研究,并对工作参数进行了优化。主要研究内容如下:(1)建立了大型半自磨机离散元模型,得到筒体最外层单个介质脱离角和上升高度值。结合介质运动理论,计算得出脱离角和上升高度的理论结果,并将理论计算结果与仿真结果进行了对比。结果表明仿真值与理论值误差较小,验证了离散元模型的合理性。(2)通过试验测试,得到不同钢球填充数量的运动轨迹。建立了试验磨机离散元等效模型,并对钢球运动轨迹进行了模拟,将试验测试结果与等效模型的离散元仿真结果进行了对比分析。结果表明试验与仿真得到的钢球运动轨迹较一致,验证了等效离散元模型仿真分析的合理性,进而验证了将离散元软件EDEM应用于大型半自磨机磨矿性能仿真分析的可行性。(3)结合颗粒累积破碎模型和衬板磨损模型,研究了不同工作参数(转速率、填充率、衬板高度、倾角、数量)对介质运动状态、功率、钢球与矿料的有效碰撞次数和衬板最大磨损高度的影响规律,获得工作参数的较优取值范围。(4)基于均匀设计方法,对工作参数进行了优化分析。建立了25组仿真方案,通过二次多项式逐步回归分析和方差分析,得到了参数与评价指标间的数学模型,并进一步得到每一指标下的最佳工作参数组合。结果表明磨矿性能评价指标分别取最优值时,最佳工作参数组合并不一致。(5)基于层次分析法,建立了磨矿性能的综合评价数学模型。通过判断矩阵的构造与一致性检验,结合不同层次结构的相对重要性权值计算,得到了综合评价指标下的最佳工作参数组合,并与原工况结果进行了对比。结果表明当转速率为84%、填充率为35%、衬板数量为52、高度为200 mm和倾角为35°时,比功率、钢球与矿料有效碰撞次数分别提高了10.78%、15.47%,衬板最大磨损高度值降低了10.81%,综合磨矿性能提高了17.25%。本文结合均匀设计法和层次分析法,对半自磨机工作参数进行了优化分析,有效改善了磨机磨矿性能,为大型半自磨机磨矿性能的研究提供了参考依据。
[Abstract]:Semi-autogenous mill is one of the main equipment in ore dressing, and its "large scale" has become the main developing trend of grinding equipment. In view of the problem of high power consumption and steel consumption in the actual production process of large semi-self-mill, this paper is based on the National Natural Fund (NO.51265020) "Design Theory and method of Hollow Axle heavy load hydrostatic bearing under Multi-field Coupling". Based on discrete element method, the grinding performance of a large semi-self-mill is studied, and the working parameters are optimized. The main research contents are as follows: (1) the discrete element model of large semi-self-mill is established, and the values of the outermost medium detachment angle and rising height of the cylinder are obtained. Combined with the theory of medium motion, the theoretical results of separation angle and rising height are calculated, and the theoretical results are compared with the simulation results. The results show that the error between the simulation value and the theoretical value is small, which verifies the rationality of the discrete element model. (2) through the test, the motion trajectory of different steel ball filling quantity is obtained. The discrete element equivalent model of the test mill is established and the trajectory of the ball motion is simulated. The test results are compared with the discrete element simulation results of the equivalent model. The results show that the trajectory of steel ball motion obtained by experiment and simulation is consistent, and the rationality of simulation analysis of equivalent discrete element model is verified. The feasibility of applying the discrete element software EDEM to the simulation analysis of grinding performance of large semi-self-grinding machine is verified. (3) combined with the particle cumulative crushing model and the liner wear model, different working parameters (rotation rate, filling rate) are studied. (4) based on uniform design method, the influence of lining height, inclination angle and quantity on medium motion, power, the effective collision times between steel ball and aggregate and the maximum wear height of lining plate are obtained. (4) based on the uniform design method, the optimum range of working parameters is obtained. The working parameters are optimized and analyzed. 25 groups of simulation schemes are established. By quadratic polynomial stepwise regression analysis and variance analysis, the mathematical model between the parameters and the evaluation index is obtained, and the optimal working parameter combination under each index is obtained. The results show that the combination of the best working parameters is not consistent when the grinding performance evaluation indexes are selected respectively. (5) based on the analytic hierarchy process (AHP), a comprehensive evaluation mathematical model of grinding performance is established. Through the construction and consistency test of judgment matrix, combined with the calculation of relative importance weight of different hierarchical structures, the optimal working parameters combination under the comprehensive evaluation index is obtained, and the results are compared with the results of the original working conditions. The results show that when the rotation rate is 84, the filling ratio is 35, the number of linings is 52, the height is 200 mm and the inclination angle is 35 掳, the specific power and the effective collision times between the steel ball and the mineral material are increased by 10.78 and 15.47, respectively. The maximum wear height of the liner is reduced by 10.81 and the comprehensive grinding performance is improved by 17.25. Based on the uniform design method and the analytic hierarchy process, the working parameters of the semi-self-grinding machine are optimized and analyzed in this paper, which effectively improves the grinding performance of the mill and provides a reference for the study of the grinding performance of the large-scale semi-self-grinding machine.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD453

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