Application of the underground natural brines for energy coal enrichment

Abstract

As part of the development of coal generation in the Russian Federation, one of the important issues is the use of enrichment processes for thermal coal. There are a large number of mineral processing methods, namely: gravity processing, flotation processing, methods of magnetic and electrical processing, as well as special processing methods, from which there are: radiometric, chemical and mechanical methods of coal preparation. Based on the results of an economic evaluation of existing enrichment methods, the team of authors identifies the gravity enrichment method as the most applicable method for thermal coals in view of the low cost of the resulting coal concentrate during its implementation. Among the existing methods of gravitational enrichment, one can distinguish enrichment in a heavy medium, as the most easily implemented, and again, the cheapest of all existing methods of gravitational enrichment. In industry, magnetite and water-sand suspensions are most often used as a heavy medium. The advantage of using these difficult media is the depth of the enrichment process - the output of coal concentrate and the amount of valuable rock recovered (combustible part of the fuel). The downside is the difficulty in operation - the suspensions must be homogenized, and the contamination of the resulting coal concentrate with weighting particles (magnetite or sand), which reduces the amount of valuable rock. It is proposed to solve this problem by using sodium chloride and calcium chloride as a natural medium in underground brines. According to the results of the work, the main indicators of the enrichment processes are estimated when using brines as a dividing medium.