陕南地区石煤矸石中主要伴生元素迁移规律研究

Study on migration law of main associated elements in stone coal gangue in southern Shaanxi

石煤是特殊的煤,因其伴生多种元素而被重视。陕南地区石煤资源丰富,石煤矸石中伴生有多种有害元素。为查明石煤中有害元素向周边环境的迁移能力及规律,通过测试石煤及其矸石中钒、铬、钼、磷元素的含量,发现陕南石煤样品中钒、铬、钼、磷元素含量较高,普遍高于中国煤中元素含量均值,钼元素富集特征明显。矸石样品中也普遍富集钒、铬、钼、磷元素。利用浸泡试验模拟4种条件下石煤矸石中钒、铬、钼、磷元素的浸出(迁移)过程,试验周期长12个月,计算了浸泡条件下矸石样品中4种元素的浸出率,结果显示:酸性环境更有利于钒元素迁移,偏酸、偏碱条件都能增大铬元素的迁移性能;石煤矸石样品钼元素在4种类型溶液中迁移能力总体较弱,酸性环境更有利于磷元素迁移,而碱性环境能抑制磷元素的迁出;石煤矸石中钒、铬、磷元素在酸性溶液具有较高的浸出率,不同样品中钒、铬、磷元素浸出率变化趋势相似,石煤矸石中钒、铬、钼、磷元素在碱性溶液的浸出效率总体较低,碱性环境在一定程度上对矸石中钼和磷的迁出存在抑制现象。石煤矸石中钒、铬、钼、磷元素在矿井水溶液的浸出效率总体不高,矿区周边水环境有利于铬和磷元素的迁移,应当引起高度重视。

Stone coal is a special kind of coal which is famous for its associated elements.The southern Shaanxi area is rich in stone coal resources.There are many harmful elements associated with stone coal and its vermiculite in this area.By testing the contents of vanadium,chromium,molybdenum and phosphorus in stone coal and its vermiculite,it is found that the content of vanadium,chromium,molybdenum and phosphorus in the samples of southern Shaanxi stone coal is generally higher than that of Chinese coal.The characteristic of element enrichment molybdenum is obvious.Vanadium,chromium,molybdenum and phosphorus are also commonly enriched in vermiculite samples.The leaching experiment was carried out to simulate the leaching(migration)of vanadium,chromium,molybdenum and phosphorus in stone coal gangue under four conditions.The experimental period was up to 12 months,and the leaching rate of four elements in the meteorite sample under immersion conditions was calculated.The results show that the acidic environment is more conducive to the migration of vanadium.The acid and alkali conditions can increase the migration of chromium.The migration of molybdenum in the stone gangue sample is weak in the four types of solutions.The acidic environment is more conducive to the migration of phosphorus,and the alkaline environment inhibits the migration of phosphorus to a certain extent.The acidic solution has higher leaching rate for vanadium,chromium and phosphorus in stone coal gangue.The leaching rates of vanadium,chromium and phosphorus in different samples are similar.The leaching efficiency of alkaline solution for vanadium,chromium,molybdenum and phosphorus in stone coal gangue is generally low,and the alkaline environment inhibits the migration of molybdenum and phosphorus in vermiculite to some extent.The leaching efficiency of the four aqueous elements of vanadium,chromium,molybdenum and phosphorus in the coal gangue is not high.The water environment around the mining area is conducive to the migration of chromium and phosphorus,which should be highly valued.