Research On The Dynamic Test Of Second-stage Grinding And The Prediction Model Of Grinding Product Particle Size In Yimen Coppe

Grinding operations are widely used in non-ferrous,metallurgical and chemical industries.Through the impact and grinding of the grinding media on the ore itself,the ore particle size is gradually reduced to provide the appropriate size and high monomer dissociation of the grinding products for subsequent separation operations.Therefore,the quality of the grinding product has an important impact on the technical and economic indicators of the whole processing plant.At present,the grinding media used in the fine grinding stage are mainly steel balls and steel segments,and the different sizes and shapes of grinding media have a significant impact on the grinding product quality.This is a theoretical and experimental basis for accurate prediction of the particle size distribution of the second stage of the Yimen Copper Mill,which is of great significance.Based on the research project"Key Technology Research on Improving Grinding Efficiency of Slag Mill",this thesis addresses the problems of low fineness and coarse particle size composition of the grinding product in the second stage of Yimeng Copper Industry,and based on the overall equilibrium kinetic model and the grinding kinetic principle,single and mixed particle size batch grinding tests were conducted to obtain the S_i.The S_i value of the crushing rate function and the b_ij value of the rupture distribution function are used as the basic parameters of the grinding product size prediction model to provide a theoretical basis for predicting the size composition of the grinding product in the laboratory stage.The results showed that the best crushing effect ofΦ40 mm steel balls and D×L35×40 mm steel section on+0.15 mm material,Φ30 mm steel balls and D×L 25×30mm steel section on-0.15+0.1 mm material,and D×L 20×25 mm steel section on-0.15+0.1 mm material.Based on the particle crushing theory,a specific optimum grinding size ratio can be obtained when the increment of specific surface area is the largest,and the grinding efficiency is the highest at this time,and the above research results are verified;according to the overall equilibrium kinetic model of grinding and the G-H algorithm,the crushing rate function of different single size grinding media can be obtained.Based on the overall equilibrium kinetic model of grinding and the G-H algorithm,the S_i value of the crushing rate function and the b_ij value of the rupture distribution function can be obtained for the prediction model of grinding product size.The results show that the grinding efficiency is higher when the grinding media ratio 1,single sizeΦ30 mm steel ball and D×L 20×25 mm steel section are used as grinding media.According to the overall equilibrium kinetic model of grinding and the Austin-Lecky BII method,the Si values of the crushing rate function and the bij values of the rupture distribution function of the single sizeΦ30 mm steel ball and D×L 20×25mm steel section can be obtained for the grinding product size prediction model.The results of the experimental study on the grinding characteristics of mixed grain size showed that,comparing the grinding time to reach the specified grinding fineness with different grinding media schemes,the best grinding effect was achieved with the grinding media ratio scheme 1,and the recommended initial ball ratio for the second stage ball mill of Yi Men Copper was Φ50:Φ40:Φ30:Φ20=15:15:40:30.The grinding parameters（crushing rate function Si and breakage distribution function bij）obtained from single size Φ30 mm steel ball and D×L 20×25 mm steel section in the single grain test were compared with the grinding media proportioning scheme 1,single size Φ30 mm steel ball and D×L 20×25 mm steel section in the mixed grain test by using Simulink toolbox in MATLAB.The grinding characteristics parameters(S_i and b_ij)of the single sizeΦ30 mm steel ball and D×L 20×25 mm steel section were input into the grinding product size prediction model,and the prediction results of the grinding product size prediction model were less inaccurate and more accurate than the grinding test results in the same grinding time.