Recovering Cu From Tailing Of A Magnetic Plant And Research On Thiosulfate Leach Au

Aiming at a magnetic tailings in AnHui, the paper contains recovering Cu and research on thiosulfate leach Au. The tailings have large in the magnetic plant, the content of Cu and Au is low included in tailings. Au distributes in the contact between green screens stone and pyrite; chalcopyrite is the main minerals, showing irregular granular and angular more, most chalcopyrite are more pure and don't contain other minerals, some chalcopyrite crack are more developed, and the crack are more filled with gangue minerals. There are two distributed morphology of chalcopyrite:(a)independent crystal (b) distributed in pyrite.The difficulty of the tailings of the magnetic plant is recovering Cu and thiosulfate leach Au. The reports of recovering Cu from magnetite tailing are little home and world. Against the refractory tailings, conducted serial research, including mineralogy, mineral process experiment and thiosulfate leach Au, the main results as follows:(1) the magnetic tailings are Au-bearing ores, metal mineral have pyrite, chalcopyrite, and few magnetite, hematite, marcasite, and trace pyrrhotite, natural Au; gangue mineral have quartz, calcite, and few garnet, green screens stone, feldspar, mica. Recognizing the main mineral content, crystal size, inlay relation and distribution law clearly. In terms of the tailings, can recover Cu, Au, S as the accessory product.(2) Aiming at the quality of tailing ,find out the process: Cu and S floating mixed- Cu and S mixed concentrate mill again-Cu and S separate. According to the mill theory of middle mine mill selective again, when Cu and S separate, except Cu and S separation sweep second and concentrate, others mill again, finally form closed cycle process, can increase flotation index dramatically. The last index: Cu22.13%, recovery rate 81.88%; S46.58%, recovery rate78.47%; Au3.38g/t, recovery rate 91.70%.(3) Adopting the process of the green environmental protection thiosulfate leach Au. Find the optimum condition: at normal temperature and pressure, l:s=3:l, sodium thiosulfate 75g/l, (NH₄)₂SO₄50g/l, CuSO₄5g/l, pH=9.5(NH₃·H₂O), 4h. The leaching rate is 90%.This paper supplies the technical feasible and economic reasonable process cycle and condition, at the same time, has guidance significance for second tap tailing.