白云质岩石中酸不溶物对碱白云石反应的影响

Influence of acid-insoluble residue on dedolomite reaction in dolomitic rocks

采用激光共聚焦显微镜(LSCM)、背散射电子显微镜(BSEM)、滴定分析和X线衍射等分析了岩石中酸不溶物(AIR)与白云石的分布、浸泡于碱溶液中的岩石柱内部的OH-含量和去白云化反应(ADR)生成的水镁石的含量。结果表明:OH-优先由岩石的酸不溶物富集区域迁入岩石内部,酸不溶物富集区域的去白云化反应程度高于非酸不溶物富集区域。酸不溶物的含量越高,OH-的迁移越容易。连续分布的酸不溶物更有利于OH-在岩石中迁移。

The distribution of acid-insoluble residue(AIR)and dolomite rocks were investigated by laser scanning microscope(LSCM)and back scattered electron microscope(BSEM).The content of OH-in different sections of the rock prisms were measured by titration.The content of brucite formed by dedolomite reaction(ADR)were determined by quantitative X-ray diffraction analysis in different sections of rocks.Results showed that OH-were prone to enter rocks through the AIR-richened zones.The degree of dedolomitization in AIR-richened zones was higher than that in AIR-lacked zones.The higher the content of AIR,the easier the migration of OH-.Continuously distributed AIR was more conducive to the migration of OH-in the rocks.