由盐田水氯镁石制取食品级氯化镁的研究

Preparation of Food-grade Magnesium Chloride by Bischofite from Solar Pond

研究了氯化镁原矿与二次水的溶解实验,采用ICP和XRD对滤液及滤渣组成进行了分析。结果表明:100 mL二次水溶解350 g氯化镁原矿,经过滤后滤液中NaCl、KCl和CaSO_4含量达到最低值。滤液经一段和二段蒸发水量分别为16.25 g和45.34 g,二段蒸发结晶产品的杂质NaCl、KCl和CaSO_4含量(%)达到最低值,分别为0.46、0.12和0.042。通过溶解实验,在最大程度上增大了溶液中氯化镁的质量分数,减少了溶液中杂质含量,为一段蒸发析晶除杂及二段蒸发结晶降低了能耗、节约了生产成本。

The dissolution-recrystallization process of magnesium chloride minerals in the distilled water were studied at a series of conditions. The compositions of filtrates and residues were analyzed and characterized using ICP and XRD. The results show that the contents of NaC1, KC1 and CaSO4 in the filtrate decreased to the minimum value after treatment at the condition of 350 g magnesium chloride and 100 mL distilled water. Then the impurity contents of NaC1, KC1 and CaSO4 in the MgC12 · 6H2O crystal product reached to a minimum value after evaporating water of 16. 25 g and 45.34 g in the first and second evapo- ration steps, respectively, and completely met the national standard GB 25584 -2010. The magnesium chloride mineral was greatly purified after dissolution treatment in distilled water at proper condition and the process was of low energy consumption and economic cost.