| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve the problems that the conventional method of leaching zinc concentrates needs many equipments such as roasting equipment, sulfuric acid recovery equipment, independent oxidation equipment for divalent iron ions and, many stages are required for the leaching of zinc and it takes a long time, therefor, then the shortening of the leaching time and reduction of equipment expenses are required. SOLUTION: A liquid containing free sulfuric acid and divalent iron ions and zinc concentrates are charged into an autoclave, and gaseous oxygen is fed thereto in a pressurizing atmosphere, and they are heated to 90 to 120 deg.C, so that divalent iron ions in the liquid are oxidized to control the concentration of trivalent iron ions to 2 to 60 g/L, and pressure leaching of zinc concentrates is simultaneously performed in one process. Further, slurry after the pressure leaching is subjected to a grinding leaching stage where simple substance sulfur by-produced on the surface of the grains of the zinc concentrates subjected to the leaching treatment is peeled and leached. Next, the slurry after the grinding leaching is gain subjected to the above pressure leaching.</p> |
