A Study on Release Law of Arsenic in Coal and Coal Gangue

Abstract

The release characteristics of arsenic in coal and coal gangue was discussed in this paper. At firsrt, Coal and coal gangue were sampled in the study area, determination of the arsenic content and sulfur content in the coal. Then the occurrence of the arsenic was analyzed in coal by chemical extraction experiment , the characteristics of mineral distribution was analyzed by X-ray diffraction (XRD) method in the coal sample. At last, the release law of arsenic in coal and coal gangue was analyzed by coal combustion experiment and leaching experiment. The results showed that, with the combustion temperature increasing during the coal combustion process, the release rate of arsenic in coal increase the arsenic content in coal residue ash decrease gradually. In different temperature combustion process, the arsenic content in coal residue ash almostly no change, however, the release of arsenic rate had a significant difference between them. The release of calcium carbonate mineral composition of arsenic in coal had inhibitory effect The influence of the pH value of leaching liquor on the leaching amount of arsenic in coal gangue is great, the higher the acidity of leaching liquor, the greater the precipitation amount of arsenic in coal gangue. The arsenic content precipitated from coal gangue is relatively large in the initial leaching, while the arsenic content decreased with the leaching amount increasing.