(NH4)2SO4-NH3-H2O体系浸出高碱性脉石低品位氧化铜矿

以高碱性脉石低品位氧化铜矿为研究对象，针对该矿样钙镁含量高的特点，采用氨水-硫酸铵浸出体系进行了常温常压浸出实验.针对该矿样的主要含铜矿物孔雀石(Cu₂(OH)₂CO₃)，基于质量和电荷的双守恒的条件下构建的浸出体系中建立Cu₂(OH)₂CO₃-(NH₄)₂SO₄-NH₃-H₂O的热力学模型，采用Matlab的拟合功能与diff和solve函数算出不同硫酸铵浓度时氨浸出孔雀石的最佳氨浓度和总铜离子浓度.实验考察了浸出氨水浓度、氨铵比、液固比对铜浸出率的影响.实验结果表明，高碱性脉石氧化铜矿石适宜浸出条件为氨水浓度1.2mol/L，氨铵比2∶1，液固比3∶1，该条件下铜浸出率较高，达到约70%.实验结果与热力学计算结果基本吻合.

Leaching of High-Alkaline Gangue Low-Grade Copper Oxide Ore in (NH4)2SO4-NH3-H2O Solution

A low-grade copper oxide ore with highly alkaline was treated. According to the characteristics of the solution with the high content of calcium and magnesium， ammonia-ammonium sulfate leaching system was adopted to conduct leaching experiment for recovering copper from a low-grade oxidized copper ore. The thermodynamic model of Cu₂(OH)₂CO₃-(NH₄)₂SO₄-NH₃-H₂O was established in the leaching system of malachite (Cu₂(OH)₂CO₃) under the condition of double conservation of mass and charge. The fitting function of the Matlab software and the diff and solve functions were used to calculate the optimal ammonia concentration and total copper ion concentration of malachite under different ammonium sulfate concentrations， respectively. Parameters， such as ammonia concentration， ammonia-ammonium ratio and liquid-solid ratio were optimized. The results indicate that the appropriate conditions include an ammonia concentration of 1.2mol/L， an ammonia-ammonium ratio of 2∶1 and a liquid-solid ratio of 3∶1. Under these conditions， the copper leaching rate reaches ~70%. The calculated results are basically consistent with the experimental measurements.