Concepedia

Abstract

Domestic combustion of coal for residential heating and food preparation is pervasive in the mountainous regions of Guizhou Province, SW China. The use of locally mined, high-arsenic (> 100 ppm) coals has caused an excess of 3,000 cases of arsenic poisoning restricted to several villages. Samples of several high-As coals are being studied to determine the concentrations, distributions, and form(s) of the arsenic. This information should help to determine the source of the As and better understand its behavior during the combustion process. Preliminary results from selected coal samples indicate that As contents are as high as 35,000 ppm, on a whole coal basis. The coals contain multiple As-bearing phases including arsenopyrite, As-bearing pyrite, arsenic sulfide (realgar?), Fe-As oxide, As-bearing K-Fe-sulfate (jarosite?), and As-bearing iron phosphate. Some of the organic matter appears to be suffused with organically-bound As or contains extremely fine particles of an As-rich phase, apparently an arsenate.