摘要
【研究目的】中国不可溶性钾岩资源十分丰富,其中以贵州万山地区尤为富集,但含钾页岩中钾的赋存状态及其富集机制尚不十分明确。【研究方法】以贵州万山地区的含钾页岩为重点研究对象,开展系统的矿相学和元素地球化学分析,探讨钾的富集作用和利用潜力。【研究结果】含钾页岩中的K主要以离子形式赋存在微斜长石中(42.43%~74.22%),其次分布在伊利石中(<25.27%),少量存在于伊-蒙间层矿物中(<5.10%)。研究区样品的元素地球化学特征表明,含钾页岩形成于被动大陆边缘,沉积物质主要来自陆源碎屑。含钾页岩的Al_(2)O_(3)/TiO_(2)值为21.37~30.17(平均25.28),Sc/Th值为0.85~1.20(平均.1.08),表明其物质来源于长英质岩石。样品的U/Th、U_(自生)、δU、V/Cr、Ni/Co和V/(V+Ni)值一致反映含钾页岩整体形成于氧化环境。含钾页岩的CIA值介于60.78~71.04之间(平均64.99),ICV值为1~1.72(平均1.18),反映源区物质经历了中等风化作用。【结论】综合A-CN-K图解和岩石矿物学特征,表明风化过程中斜长石被钾长石取代的钾交代作用促进了钾的富集。该岩石类型的钾资源(含钾页岩)在一定时期内难以有效利用,但随着今后钾资源需求的增加和开发利用技术的发展,其可能具有重要利用前景。
[Objective]China is rich in insoluble potassium mineral resources,especially in the Wanshan area of Guizhou Province.However,the occurrence state and enrichment mechanisms of potassium in potassium-bearing shales remain poorly understood.[Methods]We focus on the potassium-bearing shales in the Wanshan area of Guizhou Province,conducting systematic mineralogical and elemental geochemical analyses to evaluate potassium enrichment processes and utilization potential.[Results]In potassium-bearing shales,potassium primarily occurs in an ionic form within microcline(42.43%~74.22%),followed by illite(<25.27%),with minor amounts present in illite-smectite mixed-layer minerals(<5.10%).The ratios of Al/(Al+Fe+Mn),Fe/Ti,(Fe+Mn)/Ti,MnO/TiO2,U/Th,LaN/CeN,and LaN/YbN,along with the K2O/Na2O-SiO2/Al2O3,SiO2-K2O/Na2O,SiO2-Al2O3,and Cr-Zr diagrams,as well as the rare earth element(REE)distribution patterns,collectively indicate that the potassium-bearing shales were formed in a passive continental margin,with sedimentary materials primarily derived from terrigenous debris.The Al2O3/TiO2 ratios in the potassium-bearing shales range from 21.37 to 30.17(average 25.28),and the Sc/Th ratios range from 0.85 to 1.20(average 1.08),indicating a source material derived from felsic rocks.The values of U/Th,authigenic U,δU,V/Cr,Ni/Co,and V/(V+Ni)consistently indicate that the potassium-bearing shales were formed in an oxidizing environment.The CIA values and ICV values of potassium-bearing shales are 60.78~71.04(average 64.99)and 1~1.72(average 1.18),respectively,reflecting that the sedimentary material has undergone moderate weathering.[Conclusions]Integrated A-CN-K diagram and mineralogical composition of rocks indicate that potassium metasomatism,involving the replacement of plagioclase by K-feldspar during weathering,significantly promoted potassium enrichment.Potassium resources in potassium-bearing shales are difficult to utilize effectively in the short term.However,with future increases in potassium demand and advancements in extraction technology,they may hold significant potential for utilization.
作者
李松涛
张兵强
蒋天锐
杨成富
赵富远
王泽鹏
钱应强
谢小明
赵平
苏特
黄丹
周光红
LI Songtao;ZHANG Bingqiang;JIANG Tianrui;YANG Chengfu;ZHAO Fuyuan;WANG Zepeng;QIAN Yingqiang;XIE Xiaoming;ZHAO Ping;SU Te;HUANG Dan;ZHOU Guanghong(School of Geography and Resources,Guizhou Education University,Guiyang 550018,Guizhou,China;105 Geological Team,Guizhou Geology and Mineral Bureau,Guiyang 550018,Guizhou,China;College of Resources and Environment Engineering,Guizhou University,Guiyang 550018,Guizhou,China;103 Geological Team,Guizhou Geology and Mineral Bureau,Tongren 554300,Guizhou,China)
出处
《地质通报》
北大核心
2025年第9期1607-1628,共22页
Geological Bulletin of China
基金
铜仁市科技局基础研究计划项目《铜仁地区钾矿资源富集规律及靶区优选研究》(编号:铜市科研[2021]39号)
教育部“春晖计划”合作科研项目《贵州滥木厂矿床关键金属铊超常富集机制》(编号:HZKY20220235)。
关键词
含钾页岩
钾富集
赋存状态
物质来源
贵州万山
potassium-bearing shale
potassium enrichment
element occurrence
material source
Wanshan,Guizhou Province
