提高某选矿厂干选指标的试验研究

Experimental Study on Improving Dry Preconcentration Indicators in a Dressing Plant

针对内蒙古某铁矿选矿厂细粒级矿物干式预选抛尾中存在的处理量不足和磁团聚问题,采用风重磁联合分选的思路,对干式筒式磁选机进行了结构上的改进,并通过试验样机考察了在干式磁选过程中向分选腔通入空气后选矿指标的变化情况。结果表明:对同一批TFe品位13.51%,mFe品位3.98%,粒级-4mm的原矿物料进行分选时,随着风速的增大,分选腔内产生的涡流和湍流对粒子间的解聚效果更为显著。当滚筒转速为130r/min,风速为25 m/s,料层厚度为30 mm时,可抛除产率为89.48%、mFe品位为0.77%的尾矿,获得mFe品位为31.03%、回收率82.71%的预选精矿。与无风情况相比,精矿mFe品位可提高4.01个百分点,尾矿mFe品位可降低0.32个百分点,使该选矿厂的干式预选指标得到了一定的改善。

In view of the problems of insufficient processing capacity and magnetic agglomeration in the dry preconcentration of the fine crushing products in a dressing plant in Inner Mongolia,the structure of dry magnetic separator was improved with the idea of wind-gravity-magnetic separation.During the dry magnetic separation,the change of mineral beneficiation indicators after the air was fed into the separation chamber was investigated by using the experimental prototype.The results show that,for the same batch of raw ore with TFe grade of 13.51%,mFe grade of 3.98%,and particle size of-4 mm,with the increase of wind speed,the formation of vortex and the turbulence in separation chamber has a more significant effect on the depolymerization between particles.When the rotation speed is 130 r/min,the wind speed is 25 m/s,and the material thickness is 30 mm,the tailings with mFe grade of 0.77%and high yield of 89.48%can be discarded,and the concentrate with mFe grade of 31.03%and recovery rate of 82.71%can be obtained.Compared with the situation without wind,the mFe grade of concentrate can be increased by 4.01 percentage points,and the mFe grade of tailings can be reduced by 0.32 percentage points,so that the dry preconcentration indicators of the concentrator can be improved to a certain extent.