Mineral Solubilities in CO₂-Saturated NaCl Brine Systems

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• 作者：Sebastian Fischer^a ; ^b ; ^{fischer@gfz-potsdam.de} ; Axel Liebscher^a
• 关键词：CO2-brine-mineral interaction ; Monomineralic illite and labradorite separates ; Batch experiments
• 刊名：Procedia Earth and Planetary Science
• 出版年：2013
• 出版时间：2013
• 年：2013
• 卷：7
• 期：Complete
• 页码：260-263
• 全文大小：320 K

文摘

Experiments on CO₂-brine-mineral interactions were designed to provide kinetic data for individual rock-forming minerals. Samples of an illite-smectite mixed layer mineral and a labradorite separate were stored in flexible Ti-cells together with 2 M NaCl brine and pure CO₂ at 80 ¡ãC and 20 MPa for two and three weeks, respectively. The empirical formulae K_0.5-0.7(Mg_0.1-0.2Al_1.8-1.9)(Al_0.4-0.6Si_3.4-3.6)O₁₀(OH)₂ and Na_0.5-0.6Ca_0.4-0.5Al_1.3-1.6Si_2.4-2.6O₈ were calculated for illite and labradorite. X-ray diffraction data with Rietveld refinements reveal a pure labradorite separate. The illite separate is composed of 73.5 ¡À 1.3 wt % illite, 10.8 ¡À 1.3 wt % Ca-smectite, 11.9 ¡À 0.4 wt % orthoclase, and 3.9 ¡À 0.2 wt % quartz. Based on the acquired geochemical data, the experiments on monomineralic separates indicate (i) preferred dissolution of the Ca-smectite component out of the illite-smectite mixed layer mineral, and (ii) dissolution of labradorite.