| Semi-autogenous mill is one of the new grinding equipment which can crushing and powder the mine an the same time,it can save a piece of the crusher,so it's process is easy,it saves investments and is easy to achieve,and it's been gradually marketed in the country over the last few decades.But the investigation found that the domestic semi-automatic mill is mainly used in iron ore,molybdenum ore,copper ore and so on,the gold mine application is very few.A gold mine is the first gold mine in our country to apply ? 5.5 m(or above)semi-autogenous mill,due to the lack of experience and maintenance,after the conversion of the mineral nature,the three levels of the mining efficiency(the processing power,the handling of the single consumption,and the stability of the equipment)all have been reduced,causing a huge economic loss to the mines.Based on the above problems,this paper aims to find a set of methods to improve the grinding efficiency of wet semi-automatic grinding system in gold mines through systematic research and experiments.Through analysis,the root cause of the problem is that the ore properties have changed,so this paper starts from the ore properties,JKtech weight drop test and SMC grinding test were used to measure the hardness,impact resistance,grinding power index and other key parameters of the ore;In the second step,the methods of feeding and discharging grain size of semi-automatic mill and the flow of rock crushing were optimized,so as to give full play to the grinding function of semi-automatic mill and preliminarily optimize the load of two-stage grinding machine.Step 3,through the application of EDEM discrete element analysis software for computer simulation modeling,under various operating conditions to simulate the movement of material within the mill,and summarized the mill speed,filling rate,and the liner material structure and other key parameters on the efficiency of the mill production,and the parameters selected the optimal value,at the same time choose lighter weight for ball mill rubber lining board,further reducing the ball mill load;Finally,the selected parameters are integrated simulation research and introduced into the production of industrial tests,the research conclusions are verified.Through the application of the research results of this paper,three indicators of grinding efficiency of the concentrator have been effectively improved:ore processing capacity increased,from less than 2250t/d to about 2600t/d,increased by about 15%,concentrator reached the design processing capacity;The single consumption of grinding power decreased from 27.58kW·h/t to 20.66kW h/t,with a decrease rate of about 25%.The service life of semi-automatic mill reaches more than 7 months,which reduces the downtime,solves the problem of excessive load of ball mill and eliminates the risk of equipment damage.In addition,the load rate of semi-automatic mill increased from 53.84%to 80.77%.The load rate of ball mill decreased from 86.67%to 79.33%,and the balance of the load rate of two-stage mill was achieved.Therefore,this paper has achieved the expected results,and also proved the correctness of the research ideas and results.Through the research of this paper,the key parameters and control rules of the production efficiency control of the wet-type semi-automatic mill in gold mine are explored,which has a good reference value for the popularization and application of the semi-automatic mill. |
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