盐湖水氯镁石复合精制实验研究

盐湖水氯镁石是盐湖产业区最重要的镁资源，也是镁系列产品的主要原料。氯化镁在交通行业用于道路融雪。氯化镁作为融雪剂，对色度要求较高。实验利用活性炭加双氧水复合脱色、硫化铵化学除杂对盐湖水氯镁石的饱和溶液进行处理，获得了能满足氯化镁融雪剂要求的氯化镁精制溶液。在活性炭和双氧水加入量均为氯化镁饱合溶液质量的5%、在50℃条件下脱色处理90 min，脱色率可达94.2%。通过将脱色后溶液调成中等碱性，然后再加入硫化铵使铁、铜、锰、铅4种杂质离子以沉淀形式去除，在硫离子加入量为饱合溶液质量的0.15%、80℃条件下硫化2.0 h，最后溶液中铁、铜、锰、铅等杂质离子质量分数均低于0.000 5%。

Experimental study on compound refining of salt lake bischofite

Salt lake bischofite is the most important magnesium resource in the salt lake industrial area,and it is the main raw material of magnesium series products.Magnesium chloride is used in the transportation industry for road snowmelt,as magnesium chloride snow melting agent,which has high requirements on the color of the product.In this experiment,the saturated solution of the salt lake bischofite was processed by the composite decolorization of activated carbon and hydrogen peroxide and the chemical impurity removal of ammonium sulfide to obtain a refined magnesium chloride solution that could meet the requirements of the magnesium chloride snow melting agent.When activated carbon and hydrogen peroxide were added at 5% and 50 ℃ for 90 min,the decolorization rate could reach 94.2%.By adjusting the decolorized solution to moderately alkaline and then adding ammonium sulfide,Fe,Cu,Mn and Pb ions were removed in the form of precipitation.The content of Fe,Cu,Mn,Pb impurity ions in the final solution were all less than 0.000 5% under the condition of 0.15% sulfur ion addition and vulcanization at 80 ℃ for 2.0 h.