| SAG mills are the core equipment for grinding operations,which have been widely used in mining,metallurgy,aerospace,materials,construction and other fields.As a key component of the SAG mills,the cylinder liner has the function of protecting the cylinder of the SAG mills and transferring energy.The optimized shape of cylinder liner has an important impact on improving the grinding performance of the SAG mill,reducing energy consumption,and extending operating time of liner.DEM method has many advantages in the study of shape optimization of SAG mill cylinder liner,which has been widely concerned and deeply studied by experts and scholars at home and abroad.In this paper,Combined with the actual production situation of the Kalatongke copper-nickel ore plant,the?5.5m×1.8m SAG mill cylinder lining plate of the plants was chosed as the research object,the DEM method was selected as the experiment method,the influence law of lifter bar's parameters on load,ball motion state,and internal collision energy in the mill were analyzed;The lifter face angle,lifter height,and lifter width that affected the accumulated collision energy between the liner and the(ore + medium)were selected to design the orthogonal test schemes with orthogonal design method,and the DEM simulation experiment research were carried out,the lifter bar parameters of optimization schemes were determined with the method of variance analysis and range analysis.Theoretical basis for improving the operating time of the SAG mill cylinder and grinding quality of the Kalatongke Copper-nickel ore Concentrator was provided.The influence law of lifting bar parameters on the load and ball motion form and collision energy was analyzed by discrete element simulation,and it was found that as the width of the lifter bar increased,the falling displacement of motion medium in the horizontal direction increased slightly,and as the lifter face angle and lifter height increased,the height of the lifting load,the horizontal displacement,and the severity of the impact on the liner increased accordingly;as the height and width of the lifter bar increased,the accumulated collision energy between(ore + medium)and the liner first decreased and then increased,and the accumulated collision energy of other types first increased and then decreased.As the face angle of the lifter bar increased,the accumulated collision energy between(ore + medium)and liner first decreased and then increased,the accumulated collision energy between medium and medium first increased and then decreased,and the accumulated collision energy of the other types reached the maximum value at the face angle of 60°.The orthogonal experiment schemes were determined by the DEM method combined with the orthogonal design method,and the simulation experiment study was conducted.the best combination of lifter bar parameters of optimization scheme was determined by the method of variance analysis and range analysis.The results showed that the factors of the lifter bar were influenced by the energy consumption of the liner from strong to weak: face angle,height and width,and the face angle and height had a significant influence on the energy consumption of the liner;The best combination of lifter bar parameters was 60° face angle,190 mm height and 140 mm width;the best combination of lifter bar parameters was taken as the optimization scheme and compared with the plant scheme,the load motion pattern of the optimization scheme was more reasonable.the cumulatived collision energy between(ore + medium)and liner was reduced by 2.44 percentage points,the cumulatived collision energy between ore and ore was increased by 3.69 percentage points,and the cumulatived collision energy between medium and medium was reduced by 0.47 percentage points,which meant that the optimization scheme was more suitable for the SAG operation than the plant scheme in terms of theory.The industrial application experiment results showed that after the optimization of cylinder liner shape,the operating time of the cylinder liner was increased from108 days to 159 days,the operating time of the cylinder liner was extended by 51days;the mill operating rate was increased from 75.96% to 92.32%,and the operation rate was increased by 16.36 percentage points;the mill efficiency was increased from38.82t/h to 54.37t/h,the mill efficiency was increased 15.55t/h;the power consumption was decreased from 27.52 k W·h/t to 21.45 k W·h/t,The power consumption was decreased by 6.07 k W·h/t.the industrial application experiment results were consistent with the DEM simulation experiment results,and the reliability of the DEM method in theoretically shape optimization process of the cylinder liner was confirmed. |
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