新疆滴水低品位氧化铜矿常温氧化氨浸工艺研究

摘要

With low⁃grade copper oxide ore from Dishui county of Xinjiang Uygur Autonomous Region as raw material, factors affecting copper leaching in ( NH4 ) 2 SO4⁃NH3 system including grinding fineness, leaching time, total ammonia concentration, oxidant dosage, and ratio of NH4+∶NH3 were all investigated, resulting in the following optimal condition for leaching process, including a grinding size of -0.074 mm 86%, reaction temperature of 25℃, stirring at the speed of 200 r/min, solid/liquid ratio at 2∶1 for 1st⁃stage leaching with concentrations of ammonia, ammonium sulfate and ammonium persulfate at 3 mol/L, 1.5 mol/L and 0.15 mol/L, respectively, agitation leaching for 1.5 h followed by 0.5 hour′s standing, then with addition of ammonia, ammonium sulfate and ammonium persulfate for the 2nd⁃stage of leaching at half of previous stage, repeating agitation leaching for 1.5 h followed by 0.5 hour′s standing, and the dosage of reagent in the 3rd⁃stage leaching the same as the 2nd⁃stage, agitation leaching for 2 h followed by 4 hour′s standing. After the whole process, the leaching rate of copper can finally exceed 86%.%以新疆滴水低品位氧化铜矿为研究对象，在（ NH4）2 SO4⁃NH3浸出体系中分别考察了磨矿细度、浸出时间、总氨浓度、氧化剂用量、NH4＋∶NH3比率等因素对铜浸出率的影响。最终确定最佳工艺条件为：磨矿细度－0．074 mm粒级占86％，反应温度25℃，搅拌转速200 r／min，一段浸出液固比2∶1，过硫酸铵0．15 mol／L，氨水浓度3 mol／L，硫酸铵浓度1．5 mol／L，搅拌浸出1．5 h，静置0．5 h；二段过硫酸铵、氨水和硫酸铵添加用量减半，继续搅拌浸出1．5 h，静置0．5 h；三段浸出药剂用量与二段浸出相同，搅拌浸出2 h，静置4 h完毕。该条件下，可获得铜浸出率大于86％的优良指标。