地球学报
地毬學報
지구학보
ACTA GEOSCIENTIA SINICA
2014年
5期
572-580
,共9页
巫锡勇%廖昕%赵思远%凌斯祥%朱宝龙
巫錫勇%廖昕%趙思遠%凌斯祥%硃寶龍
무석용%료흔%조사원%릉사상%주보룡
黑色页岩:黄铁矿氧化%水岩化学作用%流通实验%动力学速率
黑色頁巖:黃鐵礦氧化%水巖化學作用%流通實驗%動力學速率
흑색혈암:황철광양화%수암화학작용%류통실험%동역학속솔
black shale%pyrite oxidation%water-rock chemical interaction%flow-through experiment%kinetic rate
水岩作用是黑色页岩化学风化的重要途径,并与岩体矿物组分、工程性质及地质环境有着密切的联系。利用自制的流通实验装置对取自三江县团结电站附近的寒武系清溪组黑色页岩与富含溶解氧去离子水的化学反应进行试验模拟研究,并利用离子分析仪、电感耦合等离子体质谱仪对反应后溶液离子浓度进行分析,使用扫描电子显微镜观察反应前后岩样微观特征,结合岩样渗透系数的变化监测,对岩样中黄铁矿氧化动力学速率以及受黄铁矿氧化影响形成的酸性环境下硅元素释放速率进行计算分析。结果表明,黄铁矿氧化行为使得岩体渗透率降低约70%,在黑色页岩自身矿物化学组分和岩石物理性质的共同影响下,所含黄铁矿氧化速率与纯黄铁矿颗粒的氧化速率非常接近,同时黄铁矿氧化形成的酸性溶液可溶蚀岩体中石英和伊利石,由于两者含量未能精确测定,因此所测得硅元素释放速率仅表示两者溶解的总反应速率。
水巖作用是黑色頁巖化學風化的重要途徑,併與巖體礦物組分、工程性質及地質環境有著密切的聯繫。利用自製的流通實驗裝置對取自三江縣糰結電站附近的寒武繫清溪組黑色頁巖與富含溶解氧去離子水的化學反應進行試驗模擬研究,併利用離子分析儀、電感耦閤等離子體質譜儀對反應後溶液離子濃度進行分析,使用掃描電子顯微鏡觀察反應前後巖樣微觀特徵,結閤巖樣滲透繫數的變化鑑測,對巖樣中黃鐵礦氧化動力學速率以及受黃鐵礦氧化影響形成的痠性環境下硅元素釋放速率進行計算分析。結果錶明,黃鐵礦氧化行為使得巖體滲透率降低約70%,在黑色頁巖自身礦物化學組分和巖石物理性質的共同影響下,所含黃鐵礦氧化速率與純黃鐵礦顆粒的氧化速率非常接近,同時黃鐵礦氧化形成的痠性溶液可溶蝕巖體中石英和伊利石,由于兩者含量未能精確測定,因此所測得硅元素釋放速率僅錶示兩者溶解的總反應速率。
수암작용시흑색혈암화학풍화적중요도경,병여암체광물조분、공정성질급지질배경유착밀절적련계。이용자제적류통실험장치대취자삼강현단결전참부근적한무계청계조흑색혈암여부함용해양거리자수적화학반응진행시험모의연구,병이용리자분석의、전감우합등리자체질보의대반응후용액리자농도진행분석,사용소묘전자현미경관찰반응전후암양미관특정,결합암양삼투계수적변화감측,대암양중황철광양화동역학속솔이급수황철광양화영향형성적산성배경하규원소석방속솔진행계산분석。결과표명,황철광양화행위사득암체삼투솔강저약70%,재흑색혈암자신광물화학조분화암석물이성질적공동영향하,소함황철광양화속솔여순황철광과립적양화속솔비상접근,동시황철광양화형성적산성용액가용식암체중석영화이리석,유우량자함량미능정학측정,인차소측득규원소석방속솔부표시량자용해적총반응속솔。
Being an important form of chemical weathering of black shales, the water-rock interaction is closely related to the mineral compositions, engineering properties and geological environments. A China-designed flow-through experiment was used to study the oxidation kinetic behavior of pyrite contained in black shale during the water-rock interaction. The ion concentrations of outflow solutions were measured by the ion analyzer and inductively coupled plasma mass spectrometry. The micro-features of the rock sample before and after the experiment were observed with a scanning electron microscope. Combined with the changes of rock permeability, the kinetic rate of pyrite oxidation and Si release in acid water were examined. The results obtained by the authors indicated that the behavior of pyrite oxidation caused the decrease of the rock permeability by 70%, and the oxidizing reaction coefficient of pyrite embedded in rocks under the effects of mineralogical and chemical compositions and petrophysical properties of the black shale was consistent with that of free pyrite grains reported by previous researchers. Besides, the quartz and illite were dissolved in the acidic solution produced by pyrite oxidation. Due to their uncertain content, the release rate of Si only represented their total dissolution rate.