复杂MeSO4体系初步除杂和深度净化

分别以浸出液和氟化沉淀液为原料，采用单因素法对复杂MeSO4体系氟化沉淀除钙镁和复盐沉淀深度净化进行了研究. 氟化沉淀除钙镁实验结果表明，在温度90℃、时间1.0 h、pH 3.5及NH4F用量为理论量2.0倍的优化条件下，Ca2+和Mg2+的平均去除率分别为92.98%和89.95%. 复盐沉淀深度净化实验结果表明，硫酸铵的浓度和溶液酸度是复盐沉淀深度除Si的关键，优化条件为pH=1.5~2.5、游离硫酸铵浓度2.0~2.5 mol/L、时间1.0~1.5 h和室温. 在此条件下，Fe, Mn和Zn三种主体成分的沉淀率分别是69.94%, 86.52%和96.88%，Si的去除率为54.85%.

Primary and Deep Purification of Complex System of MeSO4

In the complex system of MeSO4, the removal of Ca2+ and Mg2+ by fluorination precipitation and double salt precipitation deep purification process was studied by single factor method. The experimental results of fluorination precipitation demonstrate that the optimized conditions of fluorination precipitation process are as follows: the excess amount of NH4F is 2.0 times as theoretic consumption, precipitation time 1.0 h, reactive temperature 90℃ and the pH value 3.5. Under these conditions, the average removal rates of Ca2+ and Mg2+ are 92.98% and 89.95%, respectively. The key factors of double salt precipitation process are the excess concentration of (NH4)2SO4 and pH value of the solution. The optimized conditions of double salt precipitation process are as follows: the value of pH is 1.5~2.5, the excess concentration of (NH4)2SO4 2.0~2.5 mol/L, the precipitation time 1.0~1.5 h and the reactive temperature room temperature. Under these optimized conditions, the precipitation rates of main elements of Fe, Mn and Zn are 69.94%, 86.52% and 96.88%, respectively. And the removal rate of Si is 54.85%.