Stability of Na-, K-, and Ca-Montmorillonite at High Temperatures and Pressures: A Monte Carlo Simulation

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• 作者：Liberto de Pablo ; Maria L. Chá ; vez ; and Juan J. de Pablo
• 刊名：Langmuir
• 出版年：2005
• 出版时间：November 8, 2005
• 年：2005
• 卷：21
• 期：23
• 页码：10874 - 10884
• 全文大小：421K
• 年卷期：v.21,no.23(November 8, 2005)
• ISSN：1520-5827

文摘

Monte Carlo grand canonical molecular simulations on the hydration of Na-, K-, and Ca-montmorilloniteshow that between 333 and 533 K and 300-1300 bar Na-montmorillonite forms stable one-layer hydratesof d₀₀₁ spacings 12.64-12.38 Å, K-montmorillonite of 12.78-12.59 Å, and Ca-montmorillonite of 12.48-12.32 Å. A two-layer hydrate of 14.80 Å occurs for Na-montmorillonite at 533 K and 1300 bar, forK-montmorillonite of 15.32 Å at 533 K and 1300 bar and of 14.74 Å at 533 K and 2000 bar, and forCa-montmorillonite of 13.83 Å at 473 K and 1000 bar. Three-layer hydrates may possibly form within thesesame ranges. Outside of them, one-layer hydrates simulate as the only stable hydrates. In sedimentarybasins, the two-layer hydrate of Ca-montmorillonite will locate at 6.7 km depth and those of Na- andK-montmorillonite at 8.7 km depth; above and below these depths, the one-layer hydrates are the stablephases.