煤及煤矸石中砷的释放

研究了煤及煤矸石中砷的释放特征。采用XRD技术对煤样中的主要矿物成分进行了分析。表征结果显示，煤样中的主要矿物组成为碳酸盐矿物、硅酸盐矿物，以及一定量的SiO2、TiO2、硫化物矿物和硫酸盐矿物。实验结果表明：煤中砷的赋存形态主要以残渣态和硫化物结合态为主；在煤燃烧过程中，当燃烧温度为1 000 ℃时，1号矿井的煤样燃烧后灰渣中的砷含量为1.385 μg/g，砷的释放率为40.10%，2号矿井的煤样燃烧后灰渣中的砷含量为1.531 μg/g，砷的释放率为56.04%；在煤矸石的淋溶过程中，在淋溶液体积为100 mL的条件下，当淋溶液pH为5时淋出液中的ρ（砷）为19.27 μg/L，当淋溶液pH为7时淋出液中的ρ（砷）为7.78 μg/L。

Release of Arsenic from Coal and Coal Gangue

The release characteristics of arsenic in coal and coal gangue were studied. The mineral composition of the coal sample was analyzed by XRD. The results show that carbonate,silicate and some SiO₂,TiO₂,sulphide,sulfate are the main composition of the coal sample. The experimental results show that：The occurrence modes of arsenic in coal are mainly residual state and sulfide state；In coal combustion process,when the combustion temperature is 1 000 ℃,the arsenic content of the coal ash after combustion of coal sample from No.1 coal mine is 1.385 μg/g,the release rate of arsenic is 40.10%,while that from No.2 coal mine is 1.531 μg/g,the release rate of arsenic is 56.04%；In coal gangue leaching process,when the volume of the leaching liquor with pH 5 and pH 7 is 100 mL,the concentrations of arsenic in the leaching liquor are 19.27 μg/L and 7.78 μg/L respectively.