煤矸石中汞和砷的赋存形态研究

对煤矸石中汞、砷的赋存形态进行研究，可以为煤矸石发电过程中汞、砷的脱除提供理论依据。采用逐级化学浸提法将3个不同产地煤矸石中汞、砷的赋存形态分为可交换态、碳酸盐结合态、铁锰结合态、硫化物结合态、有机结合态和残渣态。采用不同的浸提溶液得到对应结合态的测试结果。结果表明，煤矸石中汞、砷的赋存形态具有一定的相似性。煤矸石中汞、砷主要以硫化物结合态为主，其质量分数占总汞的67.66%~72.68%，占总砷的56.71%~79.36%；其次为残渣态，其质量分数占总汞的23.70%~28.06%，占总砷的11.47%~18.02%。另外在煤矸石中砷还以少量有机结合态形式存在。 

The mode of occurrence of mercury and arsenic in coal gangues

In this paper, the modes of occurrence of Hg and As in three coal gangues were analyzed by sequential extraction procedure (SEP), aiming to provide the theoretical basis of removing mercury and arsenic in the process of power generation using coal gangue. The occurrence modes of As and Hg could be characterized as ion-exchangeable, carbonate-bound, iron-manganese oxide-bound, sulfides-bound, organic-bound and residual forms. The corresponding forms were obtained by adding different extraction solutions sequentially. The experimental results show that the sulfides-bound Hg and As are dominant form, accounting for 67.66%~72.68% and 56.71%~79.36% of the total Hg and As in the coal gangues respectively. The residual Hg and As are the second most abundant form, accounting for 23.70%~28.06% and 11.47%~18.02% of the total Hg and As in the coal gangues respectively. In addition, the content of the organic-bound As found in coal gangue is rare.