摘要
马海盐湖位于柴达木盆地中北部赛什腾凹陷内,其矿区北部矿段全新统固体钾矿大规模固液转化开采已稳定运行近十年,为钾肥生产提供了重要的资源保障。本文拟查明马海矿区北部矿段现阶段低品位固体钾盐矿物的类型和赋存特征,开展了矿物薄片鉴定、能谱扫描电镜和X射线粉晶衍射等分析测试工作,为水溶开采的可持续开发提供依据。研究发现:(1)杂卤石集中分布在70-79勘探线,以原生和后生交代成因赋存,且以前者为主。原生杂卤石呈片状、纤维状、粒状、纤维放射状和花瓣状集合体;后生交代成因的杂卤石呈浸染状和具石膏假象的毛毡状。(2)光卤石多分布在67-70勘探线,呈熔融状、他形粒状、裂纹状,与石盐、杂卤石、钾石盐等矿物共生。(3)钾石盐仅在72勘探线集中分布,呈自形-半自形立方单体,与光卤石、杂卤石、水氯镁石等矿物共生。(4)根据马海盐湖杂卤石赋存特征分析其成因可能为在气候干冷,流域补给水量减少,湖水大面积收缩和浓缩,矿区东南部富K^(+)、Mg^(2+)的硫酸镁亚型卤水与牛郎织女湖富Ca^(2+)的高盐度氯化物型卤水发生混合掺杂作用,形成了含钾镁钙硫酸盐型杂卤石钾盐矿物。高盐度氯化物型卤水在向东南部浓缩中心迁移渗透过程中,受蒸发和浓缩,便在研究区西北部形成了氯化物型光卤石、钾石盐等矿物。(5)需要根据杂卤石的赋存特征,制定相应的固液转化方案。
The Mahai Salt Lake is located in the Saishiteng Sag in the north-central part of the Qaidam Basin.The large-scale solid-liquid conversion mining of Holocene solid potash in the northern section of the mining area has been operating stably for nearly ten years,providing important potash fertilizer production.This paper intends to ascertain the types and occurrence characteristics of low-grade solid potash minerals at the current stage in the northern section of the Mahai mining area,and carry out analysis and testing work such as mineral thin slice identification,energy spectrum scanning electron microscopy and X-ray powder crystal diffraction,which are suitable for water-soluble mining,providing a basis for sustainable development.The research found that:(1)Polyhalite is concentrated near the 70-79 exploration line,with primary and epigenetic metasomatic genesis occurring,and the former dominates.The primary polyhalite is flake,fibrous,granular,fibrous radial and petal-like aggregates;the metasomatic polyhalites are disseminated and felt-like with the appearance of gypsum.(2)Carnallite is mostly distributed near the 67-70 exploration line,and it is molten,other-shaped granular,and crack-shaped.Symbiosis with salt,polyhalite,sylvine and other minerals.(3)Sylvine is only concentrated in the 72 exploration line.It is a euhedral-subhedral cubic monomer,which is symbiotic with minerals such as carnallite,polyhalite,and bischofit.(4)According to the analysis of the occurrence characteristics of polyhalite in the Mahai Salt Lake,the cause of deposition may be the cold and dry climate,which reduces the water supply in the basin,thereby causing the shrinking and concentration of lake water.The K^(+)-and Mg^(2+)-rich magnesium sulfate subtype brine in the southeastern part of the mining area is mixed and doped with the Ca^(2+)-rich chloride-type brine of the Niulang Zhinu Lake,forming a potassium-magnesium-calcium sulfate-type polyhalite potassium salt mineral.In the process of high-salinity chloride brine migration and p
作者
龙鹏宇
赵艳军
胡宇飞
杜江民
何继辉
王朝旭
LONG Peng-yu;ZHAO Yan-jun;HU Yu-fei;DU Jiang-min;HE Ji-hui;WANG Zhao-xu(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037;Hebei Key Laboratory of Strategic Critical Mineral Resources,Hebei GEO University,Shijiazhuang,Hebei 050031;College of Earth Sciences,Hebei GEO University,Shijiazhuang,Hebei 050031;Qinghai Zhonghang Resources Co.,Ltd.,Delingha,Qinghai 817000)
出处
《地球学报》
CAS
CSCD
北大核心
2022年第3期338-346,共9页
Acta Geoscientica Sinica
基金
国家重点研发计划课题“重点锂、铍成矿带成矿规律与预测评价研究与综合”(编号:2019YFC0605203)
中国地质科学院矿产资源研究所基本科研业务费项目“柴达木盆地马海盐湖深部异常富集卤水的物质来源和成矿机理研究”(编号:KK2119)
青海中航资源有限公司委托科技攻关项目“青海马海矿区浅部固体钾矿水溶开采的关键问题研究”(编号:zhzyb20210126-01)联合资助。
关键词
马海盐湖
低品位固体钾盐
钾盐矿物
赋存特征
成因
Mahai Salt Lake
low grade solid potassium salt
potash minerals
occurrence characteristics
causes
