柴达木盆地昆特依盐湖大盐滩矿区杂卤石沉积特征及成因浅论

Freezing Point Prediction for Salt-Water System

中文关键词:  大盐滩  杂卤石  固体钾盐  成因

英文关键词::Salt water system  Freezing point  Prediction

中文摘要:

      昆特依盐湖是柴达木西北部一个次级断陷盆地,大盐滩矿区即位于其中。大盐滩矿区赋存有丰富的卤水钾盐矿床,同时也沉积了储量可观的固体钾盐矿,杂卤石是主要的固体钾盐矿物。大盐滩杂卤石主要分布于矿区中南部,面积约302 km2。杂卤石主要产出于石盐粒晶间及淤泥或粘土层中,呈薄层状分布,埋深12~65 m,钻孔岩芯化学分析结果揭示,K2SO4品位在2.43%~8.78%之间,平均3.95%。对不同赋存状态的杂卤石成因进行了初步探讨,推测杂卤石成因的两种可能性:1在盐湖沉积期间,当石膏和石盐沉淀后,浓卤水和硬石膏反应而生成杂卤石,并交代了硬石膏或结晶在石盐孔洞中。2在构造较为剧烈的升降期,由于钾易被粘土物质吸附,当进一步浓缩的卤水与粘土作用便以杂卤石的形式沉积下来,此类杂卤石原生沉积的特征明显。大盐滩固体钾盐资源成矿潜力大,查明其成因和分布规律可为开发大盐滩固体钾盐提供理论支持。

英文摘要:

      :The freezing point of aqueous solutions with different concentration of 1∶1,1∶2,2∶1 and 2∶2 salt were calculated by the extended excess Gibbs energy model. For the solution of 1∶1,1∶2 salt and other salts at low concentration,the calculated freezing points agree well with reported experimental ones. Compared with the freezing points calculated by the formula of freezing point depressing,the excess Gibbs energy model is much better for freezing point calculation.