Mineral Surface after Reaction with Aqueous Solution at High Temperatures and Pressures

作     者：ZHANG Xuetong ZHANG Ronghua HU Shumin YU Wenbin 

作者机构：Open Research Laboratory of Geochemical KineticsChinese Academy of GeologicalSciences26 Baiwanzhuang RoadBeijing 100037 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2000年第74卷第2期

页      面：406-411页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 

基　　金：We would liketo thank the Ministry of Science and Technology andthe Ministry of Land and Resources for supporting ourproject The experimental results presented in thispaper were carried out with the financial support of GTB basic research 9501115 "Climbing project"95-pre-39 the National Science Foundation of China(Grant No.29673008) 

主　　题：mineral surface kinetics liquid/solid interface reaction 

摘      要：This work presents new experimental results on surface chemistry of reacting minerals and interface kinetics between mineral and aqueous solutions. These experiments were carried out using a flow reactor (packed bed reactor) of an open system as well as a continuous stirred tank reactor, CSTR. The authors measured reaction rates of such minerals as zeolite, albite and carbonate (rhodochrosite, dolomite) in various solutions, and tested corresponding mineral surface by using SEM, XPS, SIMS, etc. This paper mainly presents the experimental results of zeolite dissolution in water and in low pH solutions at room temperature, and dolomite dissolution at elevated temperatures. The results show that the release rates of Si, Al and Na of zeolite are different in most cases. The incongruent dissolution of zeolite is related to surface chemical modifications. The Na, Al and Si release rates for dissolution of albite and zeolite in water and various solutions were measured as a function of temperature, flow velocity, pH and solution composition in the reaction system. In most cases, dissolutions of both albite and zeolite are incongruent. Dissolution of dolomite is also incongruent in most cases and varied with T, pH, and nature of aqueous solutions. For dolomite dissolution, the release rates of Mg are less than those of Ca at high temperatures as T increases from 25 to 300°C. SIMS study indicates that the contents of Al, Na and Si in the leached layer of zeolite or albite surface, change with the distance from the surface, exhibiting a non-linear behaviour within a thickness range of 1000%. The distributions of Ca, Mg, Mn, H and Cl in the leached surface layer of carbonate have a non-linear behaviour too.