煤中Se、Cd在焦化过程中迁移规律的研究

利用现代分析测定仪器和实验室模拟手段,以煤及固相(焦炭)、液相焦化产物(焦油、氨水)、气相焦化产物(煤气)中有害微量元素镉(Cd)、硒(Se)为研究对象。通过测定,比较不同煤化度煤种微量元素的含量,并归纳探讨了配合煤中Cd、Se元素在焦化过程中的迁移规律。发现煤化度不同的煤中,镉元素随着煤变质程度升高而减少;硒元素含量对比:QFFM,JM和SM中含量相差不大。在模拟焦化温度1 000℃环境下,分别有45%的硒和48%的镉元素转移到焦炭中,2%的硒和7%的镉转移到氨水中,12%的硒和15%的镉转移到焦油中,并通过物料衡算,发现有41%的硒和30%的镉释放到煤气中。

Distribution of Se and Cd during coal coking

The content of trace elements such as Cd, Se in coal and coking products including solid-phase product (coke) and liquid-phase products (tar and ammonia) were determined. The contents of trace elements in coals with different ranks were compared and the distribution of Cd, Se during coal coking was discussed. It is shown that the content of Cd decreases with increasing coal rank. The content of Se in fat-coal is lower than that in gas coal, however, its content in coking coal is close to that in lean coal. Coking in a simulated temperature of 1000℃, 48% of Cd and 45% of Se remain in the coke; 7% of Cd and 2% of Se are transferred into the ammonia; 15% of Cd and 12% of Se are partitioned into the tar. Through the mass balance it is found that 30% of the Cd and 41% of the Se could potentially exist in gas phase.