摘要
选取石英和斜长石颗粒,分别加入不同氯化钠浓度的0.05mol/L乙酸钠溶液进行溶蚀实验,并测定溶液中几种常见成矿元素的含量。结果表明,石英颗粒溶液中SiO2含量随氯化钠浓度的增加逐渐降低。由此推测,石英矿物的溶蚀作用随地层水中矿化度的急剧增加而降低。斜长石颗粒溶液中,各成矿元素的含量变化比较复杂。对不同电荷数的金属离子,溶出的程度有较大差异,并随氯化钠浓度的增加表现出不同的变化趋势。此外,还讨论了高浓度卤水中无机离子的活度以及离子间的同离子效应、盐效应和阴离子与金属离子的络合效应对矿物溶蚀速率的影响。高浓度氯化钠溶液不利于骨架结构的硅氧四面体和铝氧四面体的溶蚀;同离子效应会降低长石首先溶出碱金属的速度;但盐效应以及无机阴离子Cl-的络合作用对高价金属离子的溶解有促进作用。
Experimental research on the dissolution of aluminosilicate mineral has been carried out by putting quartz and plagioclasite grains in sodium acetic solutions（0.05 mol/L） with different sodium chloride concentrations.The contents of several mineral elements in experimental solutions have been measured.The result indicates that the content of SiO2 in the solution with quartz grain reduces gradually with the increasing concentration of sodium chloride.It is therefore speculated that the dissolution of quartz reduce rapidly with the increase of salinity of formation water.In contrast,the dissolution of mineral elements in the solution with plagioclasite grain is different for metal ions with different electrovalences and shows various changing tendencies with the increa-sing concentration of sodium chloride in solution.The influences of various factors on dissolution rate,including inorganic ion activity in high-salinity brine and their common-ion effect,salt effect and chelating effect between anion and metal ion,have been studied and discussed.It is concluded that high concentration of sodium chloride is not favorable for the dissolution of silicon-oxygen tetrahedron and aluminium-oxygen tetrahedron.The commo-nion effect may slow down the preferential dissolution of alkali metal ions.While salt effect and chelating of inorganic anion Cl-may facilitate the dissolution of metal ions with high electrovalences.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2009年第5期662-667,共6页
Oil & Gas Geology
基金
国家"八五"重点科技攻关项目(85-101-1-5)
关键词
同离子效应
盐效应
络合作用
矿物溶解
矿化度
地层水
common-ion effect
salt effect
chelating
dissolution of mineral
salinity
formation water
