摘要
对微纹长石在碱性溶液中的溶解过程及表面特征变化规律进行实验研究,温度为60℃,实验溶液分别为NaOH(pH≈8)、Na2CO3,[ρ(Na+)=26μg/mL]和NaCl溶液,利用X射线光电子能谱(XPS)和ICP MS测定实验前后微纹长石的表面特征及实验溶液成分变化,结果表明,随着pH值升高,微纹长石的溶解性增强;微纹长石的溶解不是被单一反应模式所控制,而是在表面控制(surface conrtolled)、扩散控制(diffusion controlled)和次生物相形成三种过程交替进行的结果。碱性溶液中长石表面反应分三个步骤:H+与长石表面碱性阳离子交换反应;OH-联合已进入长石架状结构内部空隙,具较大结合能的Al O键逐步破裂,并生成铝的水解产物而溶出;表面形成富Si的络合物。
Dissolution of microperthite in alkaline solution at 60℃ has been studied in detail in this paper. The experiments lasted for 16 days. The reacted surface of grains was analysized by X ray photoelectron spectroscopy (XPS). The results show that the dissolution of microperthite in alkine solution is not controlled by a single factor, but a number of factors including surface-control, diffusion-control and crystal growth, and also demonstrate that reaction on the surface of microperthite involves three steps: cation exchange reaction between H^+ and alkali metal cation on the surface of microperthite; diffusion of OH^- and H^+ into the interstices of crystal lattice, leading to the destruction of reactable Al-O bond and the formation of the hydrolysate of aluminum; and formation of Si-rich complexes on the surface.
出处
《矿物学报》
CAS
CSCD
北大核心
2003年第4期333-340,共8页
Acta Mineralogica Sinica
基金
国家杰出青年基金(40025209)
关键词
微纹长石
溶解
表面控制
扩散控制
microcline
dissolution
surface-control
diffusion-control
