复盐结晶法对除菱锰矿浸出液中镁分配规律研究

Study on distribution law of magnesium in leaching solution of rhodochrosite by complex salt crystallization method

电解锰生产系统中Mg^(2+)循环累积已成为该行业的共性技术难题,研发经济实用的除镁方法,符合双碳目标背景下的技术发展方向。研究了一种复盐结晶法来控制电解锰系统中Mg^(2+)浓度。在硫酸锰溶液中加入Al_(2)(SO_(4))_(3)·18H_(2)O生成无定形态氢氧化铝,利用无定形态氢氧化铝的特殊性质,结合传统的复盐结晶技术,将硫酸锰溶液中Mg^(2+)的质量浓度控制在20 g/L以下,并获得有一定附加值的锰镁铝氧化物的前驱体。利用XRD、EDS、ICP-MS等检测手段,通过单因素和正交实验得到以下结论:当以铝镁物质的量比为0.3加入铝盐、反应温度为80℃、反应p H为6、反应时间为1 h时,Mg^(2+)分配系数为0.43、Mn^(2+)损失率为31.51%,溶液中Mg^(2+)质量浓度为17.525 g/L、Al^(3+)质量浓度为0.205×10^(-3)g/L,达到预期目标,可保证电解锰生产系统的健康运行。

The cyclic accumulation of Mg^(2+) in electrolytic manganese production system has become a common technical problem in the industry.Developing economical and practical magnesium removal method is in line with the technical development direction under the background of dual-carbon target.A complex salt crystallization method was studied to control the concentration of Mg^(2+) in electrolytic manganese system.Al_(2)(SO_(4))_(3)·18H_(2)O was added into the manganese sulfate solution to generate amorphous Al(OH)_(3).Based on the special properties of amorphous Al(OH)_(3) and the traditional double salt crys⁃tallization technology,the concentration of Mg^(2+)in the manganese sulfate solution was controlled below 20 g/L.And the precursor of Mn-Mg-Al oxide with certain added value was obtained.By means of XRD,EDS and ICP-MS,the following con⁃clusions were obtained by single factor and orthogonal experiment:when aluminum salt was added with aluminum magne⁃sium molar ratio of 0.3,the reaction temperature was 80℃,the reaction pH was 6 and the reaction time was 1 h,the Mg^(2+) distribution coefficient was 0.43,the Mn^(2+) loss rate was 31.51%,the Mg^(2+) concentration in the solution was 17.525 g/L,and the Al^(3+)concentration was 0.205×10^(-3) g/L,which reached the expected goal and ensured the healthy operation of the electro⁃lytic manganese production system.