Mineralization of Basalts in the CO2鈥揌2O鈥揝O2鈥揙2 System

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• 作者：Herbert T. Schaef ; Jake A. Horner ; Antoinette T. Owen ; Chris J. Thompson ; John S. Loring ; Bernard P. McGrail
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：May 6, 2014
• 年：2014
• 卷：48
• 期：9
• 页码：5298-5305
• 全文大小：395K
• 年卷期：v.48,no.9(May 6, 2014)
• ISSN：1520-5851

文摘

Sequestering carbon dioxide (CO₂) containing minor amounts of co-contaminants in geologic formations was investigated in the laboratory through the use of high pressure static experiments. Five different basalt samples were immersed in water equilibrated with supercritical CO₂ containing 1 wt % sulfur dioxide (SO₂) and 1 wt % oxygen (O₂) at reservoir conditions (100 bar, 90 掳C) for 48 and 98 days. Gypsum (CaSO₄) was a common precipitate, occurred early as elongated blades with striations, and served as substrates for other mineral products. In addition to gypsum, bimodal pulses of water released during dehydroxylation were key indicators, along with X-ray diffraction, for verifying the presence of jarosite鈥揳lunite group minerals. Well-developed pseudocubic jarosite crystals formed surface coatings, and in some instances, mixtures of natrojarosite and natroalunite aggregated into spherically shaped structures measuring 100 渭m in diameter. Reaction products were also characterized using infrared spectroscopy, which indicated OH and Fe鈥揙 stretching modes. The presences of jarosite鈥揳lunite group minerals were found in the lower wavenumber region from 700 to 400 cm^鈥?. A strong preferential incorporation of Fe(III) into natrojarosite was attributed to the oxidation potential of O₂. Evidence of CO₂ was detected during thermal decomposition of precipitates, suggesting the onset of mineral carbonation.