Enrichment of sludge dump coal by spiral separation

The purpose of the presented research is to study the possibility of obtaining an additional coal product and ironcontaining concentrate from the sludge of a coal hydraulic dump. The research involved the study of the material composition of the initial sludge and technological tests. Material composition was examined using chemical, granulometric and mineralogical analyzes, the technological tests were conducted according to the gravitational-magnetic enrichment scheme. A spiral separator was used as the main enrichment equipment. Finishing operation was performed by the method of wet magnetic separation. Having studied the material composition, we determined that the initial sludge of the hydraulic dump is represented by 44.7 % of black coal and 43.32 % of brown coal. The bulk of hard coal is distributed in the size range of -2+0.25 mm and makes 51.15 %, brown coal is distributed in the size range of -2+0.25 mm in the amount of 13.32 %. The material is predominantly represented by a particle size of less than 0.25 mm with a high ash content in it. A coal concentrate with the ash content of 14.4 % was obtained as a result of technological tests. This product corresponds to the brand LFF (long-flaming fine). An iron-containing concentrate with the iron mass fraction of 64.7 % can be used in the metallurgical industry or in heavy-medium separation for coal enrichment. The study illustrates the possibility of obtaining high-quality secondary raw materials without additional mining costs using environmentally friendly technology.

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