Direct Reduction Of Sphalerite Of High Iron By Reducer In Vacuum

Zinc are one of the important nonferrous metals, which plays an role in the national economy. China is rich of zinc resource, most of which exist in forms of sphalerite of high iron. The zinc smelt researchers have been studying a series technology on sphalerite of high iron for long time, however, all these technologies are difficult to industrialize because of the low zinc volatile rate, tediously flow and so on. Therefore, we carried out the theoretical and experimental study on reducing sphalerite of high iron by copper powder, iron powder and carbon and lime in vacuum. The use of this process in handling sphalerite of high iron realized direct disposing of sphalerite of high iron and has the advantages of dealing with sphalerite of high iron independently, short flow, non-pollution, high metal recovery and good comprehensive utilization and so on. It is aimed at rich and difficult handling zinc resource - sphalerite of high iron in our country, converts the resource advantage into economic superiority and has a bright future.According to the thermodynamic analysis on reducing sphalerite of high iron by reducers in vacuum, we got the following theoretical temperatures: 1123¹373K, 926 1306Kand 605⁶95K, using copper powder, iron powder and carbon and lime as reducer respectively at 1.01⁵0×1.01Pa (10^-5 5 × 10^-4atm) atm system pressure. These will provide theoretical reference on deciding reductive temperature in experimental operation.The experimental study on reducing sphalerite of high iron by reducer in vacuum gave us the optimum technique conditions, the better technique conditions in reducing sphalerite of high iron by copper powder in vacuum is: Cu/ZnS=4, reductive temperature 1123K, keeping heating for 45mins. In this condition, the zinc volatile rate was about 95%, product Cu₂S produced matte with FeS in raw. The optimum technique conditions in reducing sphalerite of high iron by copper powder in vacuum is: Fe/ZnS=2, reductive temperature 1273K, heating for 60mins.At this conditions, the zinc volatile rate was about 95%, the iron in remains existed in forms of sulfide. The better technique conditions in reducing sphalerite of high iron by carbon and lime in vacuum is: C/ZnS = 3, CaO/ZnS:=2, reductive temperature is 1173K, keeping heat for 60mins. Under these conditions, the zinc volatile rate was above 85%, sulfur element existed in form of CaS.All these theoretical study results and experimental data will provide theoreticalfoundation and experiment guarantee on the industrialization of the technology of direct reducing of sphalerite of high iron by reducer in vacuum.