氨法浸出某精矿中低含量镍铜钴的试验研究

以某深度碳还原处理后的镍冶炼渣的磁选精矿为研究对象, 对其组成以及镍、铜和钴在其中的赋存状态进行了检测和分析, 研究了浸出该精矿中铜、镍、钴的可行性。以氨水-碳酸盐缓冲溶液为浸出剂, 氧气为氧化剂, 分别探讨了物料细度、浸出时间、浸出温度、氨水浓度、铵盐浓度和氧气压力对浸出效果的影响, 得出最优浸出工艺为: 物料料度为d₉₀=68 μm, 氨水浓度为3.0 mol/L,碳酸铵浓度为0.5 mol/L, 氧气压力为0.3 MPa, 温度为60 ℃, 浸出时间为120 min。在此条件下, 铜浸出率为62.5%, 镍浸出率为10%, 钴浸出率为65.8%。并以铜为例, 对氨浸试验进行了简要的机理分析。

Experimental Study on the Ammonia Leaching of Low Content of Ni,Cu and Co from A Concentration

A magnetic concentrate of nickel smelting slag after deep carbon reduction was taken for analysis of its compositions and occurrence of Ni, Cu and Co in it, so as to investigate the feasibility of leaching of Cu, Ni, Co from the concentrate. With ammonia?carbonate buffer solution as leaching agent and oxygen as oxidizing agent, impacts of grain size, leaching time and temperature, concentration of ammonium hydroxide and ammonium salt, and oxygen pressure on the leaching effect were discussed respectively. It is found that with the following optimum conditions for leaching process: material size (d₉₀ =68 μm), concentrations of NH₄OH and (NH₄)₂CO₃ at 3.0 mol/ L and 0.5 mol/ L respectively, oxygen pressure at 0.3 MPa, leaching at 60 ℃ for 120 min, leaching rates of Cu, Ni and Co reach 62.5%, 10% and 65.8%, respectively. At the end, the kinetics of Cu leaching behavior was analyzed.