Migration and Removability of Fluorine and Chlorine from Guizhou Shuicheng Coal During Cleaning Process

In order to study the migration and removal characteristics of fluorine and chlorine in Guizhou Shuicheng(SC-DHB) coal,regressive release flotation and float-sink tests were carried out,during which the fluorine and chlorine content in the washed coal products analyzed,while the washability of original coal samples assessed.In addition,the existing forms of fluorine and chlorine in Guizhou coal,and the affinity between fluorine/chlorine and inorganic minerals were studied also.Moreover,by analyzing the removal efficiency of fluorine and chlorine via float-sink method,the removability of the two elements were estimated.Results show that when the ash content in clean coal is 10%,the floatability of Guizhou SC-DHB coal is in the moderate level,and when the ash content is 13.0%,it is in the easy level.Removability analysis results on fluorine and chlorine show that the theoretical clean coal ash content is 12.07%,indicating that the coal's washability lies between the moderate and easy level.In SC-DHB coal, fluorine mainly exists in the inorganic form and has good inorganic affinity,while a majority of chlorine exists in the inorganic form and a small fraction in the organic form,which has strong inorganic affinity.For coals containing medium mass fractions of fluorine and chlorine,the fractions can be reduced to relatively low level by coal washing.