逐级提取试验研究岩石中氟的化学活动性

使用逐级化学提取方法对岩石中氟元素的化学活动性进行了研究.结果表明,不同时代、不同类型岩石中氟的化学活动性具有很大的差异,碳酸盐岩中氟均具有很强的化学活动性,其中氟的可淋失比例一般高于75%;下寒武统黑色岩系中氟的化学活动性与岩石变质程度有关,变质程度较高的黑色碳质板岩中氟的可淋失比例一般小于黑色页岩、黑色硅质岩中氟的可淋失比例.磷块岩中氟的可淋失比例较高,而千枚岩中氟的可淋失比例一般较低;辉绿岩中氟的可淋失比例与原岩中氟含量存在正相关关系.不同时代的石煤中氟的化学活动性具有较大差异.下志留统石煤中氟的可淋失比例(平均为47.39%)一般高于下寒武统石煤中氟的可淋失比例(平均为29.43%).

Sequential Extraction Experiments Applied to Study Chemical Mobility of Fluorine in Rocks

Sequential extraction experiments were used to study the chemical mobility of fluorine in rocks.The results show that there are quite big differences in chemical mobility of fluorine in rocks of different types.Fluorine in carbonate rock is very active,in which the proportion of leachable fluorine is generally more than 75%.Fluorine in black rocks of Lower Cambrian is closely related to their different metamorphosed grades,in which fluorine in black carbonaceous slate with higher metamorphosed grade mostly has lower leachability than black shale and black siliceous rock.Generally speaking,the leachable percentage of fluorine is high in phosphorite rocks and low in phyllite.The leachable fluorine in diabase is in direct proportion to its fluorine concentration.There are some differences in chemical mobility of fluorine in stone coal of different ages.Fluorine in stone coal of Silurian has higher leachability than stone coal of Cambrian.