The use of high As-bearing coals has caused more than 3,000 cases of arsenosis patients in southwest Guizhou Province, China. The mode of occurrence of arsenic in coal is an important key role in understanding its beh...The use of high As-bearing coals has caused more than 3,000 cases of arsenosis patients in southwest Guizhou Province, China. The mode of occurrence of arsenic in coal is an important key role in understanding its behavior during usage and damage pathway to human health. Coal samples from endemic arsenosis areas were analyzed with INAA, EMPA, SEM-EDX, LTA, XRD, XAFS, and sequential leaching experiment. Arsenic in pyrite is from under the limit of EMPA to 1.75%, and in most cases, the content of arsenic is lower than 0.5%. Besides pyrite and arsenopyrite, SEM-EDX combined with LTA and XRD find that sulfates, clay and phosphates also contain arsenic. XAFS shows that arsenic mainly exists in the form of As^5＋. More than 50% of arsenic stayes in residual solid and combined with organic matrix in two samples, but most arsenic is leached out in other samples. The occurrence of such exceptionally high As contents in coal and the fact that the arsenic is dominantly organically associated are unique observations.展开更多
文摘The use of high As-bearing coals has caused more than 3,000 cases of arsenosis patients in southwest Guizhou Province, China. The mode of occurrence of arsenic in coal is an important key role in understanding its behavior during usage and damage pathway to human health. Coal samples from endemic arsenosis areas were analyzed with INAA, EMPA, SEM-EDX, LTA, XRD, XAFS, and sequential leaching experiment. Arsenic in pyrite is from under the limit of EMPA to 1.75%, and in most cases, the content of arsenic is lower than 0.5%. Besides pyrite and arsenopyrite, SEM-EDX combined with LTA and XRD find that sulfates, clay and phosphates also contain arsenic. XAFS shows that arsenic mainly exists in the form of As^5＋. More than 50% of arsenic stayes in residual solid and combined with organic matrix in two samples, but most arsenic is leached out in other samples. The occurrence of such exceptionally high As contents in coal and the fact that the arsenic is dominantly organically associated are unique observations.
