|
A large mass of tailings have been accumulated during more than ten years’ production in a iron concentrator, Teng Chong, Yun Nan province. Many other non-ferrous metals are not recovered because of limitation of productive conditions and technological level, except only magnetite. These disposal metals which exist in tailings not only bring waste of resource, but also create potential environment pollution. At present, as large scale production continues, a various kinds of resources face the problem of depletion. So the study on utilization of tailings resource should be carried out at the same time of exploitation of primary deposit, which will be very important for our national policy of sustainable development.As a commission from Teng Chong iron concentrator, studies on mineral processing for tailings from the concentrator are carried out to recover multi metals. The tailings sample contains 0.24% Sn,0.15% WO3,16.6% Fe and 1.68%S. Valuable minerals mainly include pyrite, pyrrhotite, magnetite, cassiterite and calcium tungstate, with a little content of sphalerite and bornite. And gangues mainly contain biotite, quartz, fluorite, white mica and chlorite, with a few of dolomite. According to the analytical results of chemical compositions, valuable mineral can be recovered is cassiterite. While tungsten and iron can be concentrated as by-products. Those compositions that should be eliminated and reduced are S、SiO2、MgO、CaO、Al2O3, etc.Five concentration schemes are compared in the paper, as (1) single method of gravity concentration by shaking table, (2) combined method of gravity concentration-flotation-magnetic concentration, (3) combined flowsheet of gravity concentration-magnetic concentration- flotation, (4) combined method of flotation-gravity concentration-magnetic concentration, and (5) combined method of flotation-magnetic concentration-gravity concentration. Through comparing, the best technique flowsheet is found to treat the sample, namely the fifth scheme is the best. According to the designed processing flowsheet, fine valuable products can be obtained as (1) sulphur concentrate, which contains 33.20% S at a recovery of 94.85%, (2) tin and tungsten mixed concentrate, which contains 12.77% Sn and 5.87% WO3 at a recovery of 21.28% and 19.56%, respectively, (3)tin and tungsten mixed middlings, which contains 3.28% Sn and 2.55% at a recovery of 13.94% and 17.35%, respectively, (4)iron concentrate with intensive magnetism that contains 67.28% Fe at a recovery of 4.05%, and (5)iron concentrate with weak magnetism which contains 53.68% Fe at a recovery of 53.55%.Certain results, which will give some productive guide to similar concentrators, are given out in studies on mineral processing technology in this paper.
|