A Study On Occurrence Characteristics And Precipitation Regularity Of Arsenic In A Coal Mine Of Inner Mongolia

The precipitation of arsenic of coal is one of major source of arsenic in theenvironment, the precipitation of arsenic in coal is closely related to the occurrenceforms of arsenic in coal. The research analyze the original mining area coal maceralsdata, use the mathematical statistics, make floating and sinking experiments, studysequential chemical extraction analysis arsenic occurrence forms in coal. Theprecipitation regularity of Arsenic in coal by Coal combustion experiments and gangueleaching experiment carried the environmental impact of arsenic in the mine coal.The results showed that:Arsenic content in coals range between2.209μg/g and4.565μg/g, and2coalfieldaverage mean of Arsenic is3.353μg/g, whose content is higher than1coalfield averagemean of Arsenic(2.387).The arsenic in coal mainly occurs in the organic maceral halfvitrinite and fusinite, inorganic maceral clay, sulfides and carbonates; Arsenic in coaland sulfur was significantly positively related.Coal samples with the increasedproduction rate of the ash, the arsenic content in the ash also increased accordingly,arsenic in coal with ash yield was significantly positive correlation.Arsenic content incoal and ash content increased with the increasing of density level, the ability of arsenicoccurrence to inorganic than organic. Arsenic occurrence in coal is residual arsenic＞sulfide arsenic＞organic arsenic＞soluble and exchangeable arsenic, arsenic in coalmainly occur in the inorganic component,a considerable part occur in the organiccomponents.Get the arsenic release rate of coal in different combustion temperatures by coalcombustion experiments. In the combustion process which is from450°C to1000°C,the temperature increases, the rate of release of arsenic elevated. Gangue leachingexperiment showed that the arsenic precipitates increased as the leaching solution pHreduce,and the arsenic precipitates reduce as the leaching solution increase. Calculatedthe annual precipitation amount of arsenic is61.67kg under normal annual rainfall.