| Danxia smelter has the first large-scale production line of Oxygen pressure acidleaching of sphalerite in China, it actively promotes the technological upgrading of zincsmelting production process of China. But its Second stage leaching efficiency is onlyabout92%, and Zinc grade of leaching residue is8%-10%, this seriously affects theeconomic benefit of smelter, and also causes a huge waste of zinc resources.The purpose of this project is to improve grinding efficiency of the sand millbefore second stage leaching, at the same time reduce the feed size of second stageleaching, and at last improve the efficiency of the second stage leaching. Take a varietyof factors that affect the grinding efficiency into consideration, there put forward2solutions: one is to change the natures of the feed of sand mill, for example, addhydrocyclone as classifying equipment before sand mill, pre-separate fine particle toleaching, while reducing quantity of pulp that inflow the sand mill, improving grindingefficiency; the other one is to explore suitable working parameters and mediumdiameter of sand mill, let the material gets fully grinding, so as to improve grindingefficiency.The hydrocyclone works well when put it into the processes, but the grindingefficiency is not improved by the cyclone-sand system, and the second stage leachingefficiency has not improved too. Use alumina ceramic balls replace zirconium as themill medium in the test, it can reduces the cost of production, and in the laboratory tests,it found that: the most suitable medium diameter is5mm. In commercial tset, the5mmdiameter medium works well: it can improve the content of-40μm from65%to90%orhigher, and the second stage leaching efficiency also improved2%.Improved the two stage grinding process, increased the Zn resource recovery rate,and the leaching efficiency improved2%-3%, with annual production of100000tons ofzinc calculation, it will improve the economic benefits of Danxia smelter about30000000yuan per year. |
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