The Influence of Coal Enrichment on the Chlorine Content in Coal Concentrate

The article considers the effect the gravitational enrichment in single-phase high-density media of natural and man-made origin has on the chlorine content in the coal concentrate obtained. It is pointed out that an increased content of chlorine in the applied fuel can initiate high-temperature hydrochloric acid corrosion of equipment and working surfaces, and also activate the formation of chlorine-containing organic compounds, which pose a serious threat to both the environment and human health. Studies on determining the chlorine content in the initial and enriched coal from the Kalewa field in the Republic of the Union of Myanmar were carried out. It is shown that the chlorine content after the gravitational enrichment of coal with the use of underground natural sodium chloride brines as a heavy medium increases from 0.01 to 0.20%. The chlorine content in the initial and enriched coals from the Tigyit, Kalewa, and Sintaung fields (the Republic of the Union of Myanmar), and from the Safonovo field in the Moscow brown coal basin (Russia) was studied by the method of determining the electrical conductivity of initial and enriched coal aqueous solutions. It is shown that its content in all coal samples did not exceed 0.4%. The possibility of chlorine-containing compounds to emerge and hydrochloric acid corrosion to become activated was estimated. The process of joint thermal destruction of coal and sodium chloride crystallized from the underground natural sodium chloride brine is described, based on which a conclusion has been drawn that sodium chloride does not intensify the chlorine-containing compounds and hydrogen chloride formation processes.