褐煤地下气化过程中铅和砷的迁移规律的研究

Study on the migration of lead and arsenic during underground coal gasification

在煤炭地下气化模型试验的基础上,研究了褐煤原煤及其气化产物中的铅和砷的含量和分布,进行了铅和砷的质量平衡计算,并分析了其析出的反应机理.实验结果表明,铅在原煤中以残渣态23.07%、碳酸盐和铁锰氧化物结合态53.96%、硫化物结合态22.96%存在,而砷则以残渣态47.73%、有机结合态7.95%、硫化物结合态40.90%存在.在气化过程中63.65%的铅和56.23%的砷残存在地下煤灰中,1.15%的Pb和6.62%的As转化到煤气冷凝水中,35.20%的Pb和37.15%的As转化到煤气中.

Based on model tests of underground coal gasification （ UCG）, the content and distribution of lead and arsenic in test lignite and its gasification products were studied. Their mass balances were calculated, and the reaction mechanism analyzed. The results indicate that the form of occurrence of is distributed in residue, carbonate ＆ ferromanganic oxides, sulfide-bound compound with the proportion of 23.07%, 53.96%, and 22.96% respectively, and that of arsenic is analyzed to be residue,47.73% , organic compounds, 7.95%, and sulfide-bound compound, 40.90%. During the process of UCG, 63.65% of lead and 56.23% of arsenic are left in the coal ash, 1.15% of lead and 6.62% of arsenic are transferred to the gas condensation water, and 35.20% of lead and 37.15% of arsenic are turned into coal gas.