-5℃下低品位钾硫酸镁亚型卤水的蒸发结晶规律

Research on evaporation and crystallization regularities of low grade potassium magnesium sulfate subtype brine at -5 ℃

采用低温冷冻方法研究了青海大浪滩地区低品位钾的晶间卤水在-5℃时的蒸发结晶规律。该晶间卤水为典型的硫酸镁亚型卤水,依据0℃下Na+,K+,Mg2+//Cl-,SO42-—H2O五元体系的介稳相图,绘制出在-5℃下低温冷冻时卤水的低温蒸发结晶规律。利用X射线衍射仪和偏光显微镜鉴定其固相组成。通过对不同液相组成的分析,确定了-5℃低温蒸发该晶间卤水时伴随NaCl·2H2O的析盐结晶顺序为:Na2SO4·10H2O、MgSO4·7H2O、KCl·MgCl2·6H2O、MgCl2·6H2O,该结果为低温盐田工艺的开发提供了基础数据和理论依据。

Research was conducted on the-5℃evaporation and crystallization regularities of the low grade potassium intercrystalline brine in Dalangtan area,Qinghai.The brine evaporation and crystallization regularities at-5℃ was developed based on Na＋,K＋,Mg2＋//Cl-,SO42-—H2O system metastable phase diagram at 0 ℃.The solid phase composition was analyzed by X-ray diffractometer and polarizing microscope and the intercrystalline brine in evaporation at-5 ℃ was identified by analyzing the different liquid phase compositions with the order of the resulting NaCl·2H2O salting-out crystallization being Na2SO4·10H2O、MgSO4·7H2O、KCl · MgCl2·6H2O、MgCl2 ·6H2O,which provides the basic data and the theoretical basis for the development of technology for salt pan at low temperature.