An Experiment And Study Of Using The Stone From The Discharge Of Semi-autogenous Mill Of Yinshan As Grinding Medium In The Vertical Stirred Mill

With the more large-scale development of copper ore,the mining ore grade is lower and dissemination size is finer.The vertical stirred mill is chosen resulting from that the traditional grinding process of grinding twice using ball mill cannot achieve the request of grinding fineness.Because the steel ball is the media in vertical stirred mill,the mineral surface is easily polluted leading to the change of the floatability being bigger and the floatation indexes being affected.Based on the regrinding system in the Yinshan ore treatment plant of Jiangxi Copper Corporation,a new idea is proposed that the stones,which come from the discharging of semi-autogenous mill,are used as the grinding media in the vertical stirred mill in order to mitigate the pollution of iron and save the mill cost.The grinding process is published that semi-autogenous mill,ball mill,crush and vertical stirred which uses stone.The article makes use of the rock's characteristics of mechanical properties and the stone's mechanical strength.The autogenous grinding test is carried out to turn out that the feasibility to be used as the grinding media is verified.Then the influence of grinding parameters is discussed on the stone grinding operation in the laboratory,getting the best condition of stone grinding and the consumption of stone,finding the way that the stone replace the steel ball and calculating the size of stone.Finally,the industrial test is made.After a long time of stably producing,the flotation effect is reviewed and the economic benefit is calculated.Conclusions are obtained:1.JK drop-weight impact test and abrasion test indicate that the impact resistance of the ore belonges to medium grade and the abrasion resistance of the ore is mid-hard grade both according to JK database.With the increase of buried depth,the compressive strength of ore increases and the hardness of the stones which come from the discharging of semi-autogenous mill raises.The compressive strength of the highest is in 30 to 40 mm.the result of stone autogenous shows the grinding fineness of the loser is more than 69.89% and has met the demands.2.The best grinding condition of stone grinding experiment in the laboratory is that batch grinding amount is 5kg,the grinding time is 3 min,grinding concentration is 65% and the medium filling rate is 60%.The stone is predicted to consume 13.3t/d3.It turns out that the stone has the same grinding efficiency with the equal quality steel ball from the grinding Medias study,which includes the stone,the steel ball with the same quality of stone,the steel ball with the same volume of stone and the steel ball with the equal surface area of stone.4.The experiment shows that content of the easy to be separated size of flotation feed increases by 7.37% from the industrial test of stone replacing steel ball,the recovery of the copper and sulfur add by 1.2 percent point in the two stage flotation process,the total recovery adds to 0.9 percent point.While under the condition that content of the grinding fineness of-0.045 mm is 80%.The vertical stirred mill's power is reduced 16.67%.From the experiment,it can bring economic benefits5.72 million yuan/year.