Study On Extracting Sulfur From Sulfur Residues After Treatment Zinc Sulfide Concentrates With High Content Of Iron

The resources of zinc concentrates with high content of iron widely distribute in our country. The available reserves of which is 7×10~6 tons in Yunnan Province, which occupies 1/3 of Yunnan reserves. Up to now, there is no enterprise and technology to treat them separately. Yunnan metallurgy group has independently developed the technology of pressure leaching to treat this concentrates. The topic how to extract sulfur from sulfur residues after treatment zinc sulfide concentrates with high content of iron through the method of leaching developed by Yunnan metallurgy group.I found there are two methods of recovery of sulfur from sulfur residues after searching of documents, one is physical method as: pressure decantation, high temperature filtration, floatation, forming of pellets sieving, vacuum distillation. The other is chemical method which extract sulfur by the solvent of dimethylbenzene, perchlorethylene, ammonium sulfide, coal oilkerosene and the other .The sulfur residue contains 61.06% of sulfur, most of which exist as elementary substance (>80%) a little exist as compound.The method of extracting sulfur by the solvent of ammonium sulfide and atmospheric distillation are chosen for the test after comparison the advantages and disadvantages of different methods of extraction sulfur from sulfur residues and consideration of composition and components of sulfur residues.The test of extracting sulfur by the solvent of ammonium sulfide indicates that dissolving reaction is very fast, it is easy to control and operate. But the solvent of ammonium sulfide also can dissolve Au, Pt, sulfide and other substance. Those substance remain in sulfur product when the solution is heated, this will cause the loss of precious metal and the purity of sulfur is low. So the solvent of ammonium sulfide can't be used to treat sulfur residue.The test result of atmospheric distillation indicates that this method is very available. The test has checked the effect of temperature, time, thickness of material on distillation. The result indicate that the primary effect factor is temperature, the secondary effect factor is time, the last effect factor is thickness of material. Underthe condition of 20 g and 10.75 cm2 of crucible, the best flow process condition is found as: distillation time is 20 min, distillation temperature is 460 'C. The content of sulfur in test residue has reduced to 24.32%. distillation rate of sulfur is more than 80%.