开采条件下马海盐湖地下卤水水化学演化特征

Hydrochemical evolution characteristics of underground brine under mining conditions in Mahai salt lake

为了解开采过程中卤水水化学动态特征及其演化规律,选择柴达木盆地马海盐湖开采前、开采初期和开采中后期地下卤水样品,通过统计分析、相关性分析、离子比例分析及卤水水化学类型分析等方法研究开采过程中马海盐湖地下卤水水化学动态特征,分析卤水演化规律。结果表明,开采过程中K+,Ca2+,Mg2+,SO2-4含量变化稍大,是随着环境因素而变化的敏感因子;卤水中Na+与储卤介质中吸附的Mg 2+存在离子交换作用,且存在白云石的溶解和方解石的沉淀;开采过程中卤水水化学类型并未发生改变,卤水水化学类型主要为硫酸镁亚型。

The underground brine samples before mining,on the initial stage and after mining of Mahai salt lake in Qaidam Basin were selected to understand the chemical dynamic characteristics and evolution of brine in mining process.The hydrochemical dynamic characteristics of subsurface brine in Mahai salt lake during mining were studied by means of statistical analysis,correlation analysis,ion ratio analysis and brine chemical type analysis,and the evolution law of brine were analyzed.The results showed that the variation of contents of K+,Ca 2+,Mg 2+and SO 2-4 was slightly big in the mining process,which were sensitive factors to the changes of environmental factors.There was ion exchange between Na+and Mg 2+adsorbed in the halogen storage medium in brine,together with the dissolution of dolomite and the precipitation of calcite.The hydrochemical type of brine did not changed during the mining process,which was mainly magnesium sulfate.