Method for flotation of coal from coal-containing casting fly ash

Abstract

The invention belongs to the technical field of solid waste resource recycling treatment, and particularly relates to a method for flotation of coal from coal-containing casting fly ash. The method for flotation of the coal from the coal-containing casting fly ash comprises the following steps that the coal-containing casting fly ash is subjected to ore grinding treatment to obtain ore grinding powder; the ore grinding powder is mixed with water to obtain ore pulp; the ore pulp is subjected to roughing to obtain roughed clean coal; and the roughed clean coal is sequentially subjected to first concentration and second concentration to obtain clean coal, specifically, the ash content of the clean coal is less than or equal to 14wt.%. According to the method, the purpose of stripping ettringite on the surfaces of coal particles in the coal-containing casting fly ash is achieved in an ore grinding mode, the separation degree of the coal particles and gangue minerals in the coal-containing casting fly ash can be improved, the clean coal yield of the coal-containing casting fly ash is improved, and the ash content of the clean coal is reduced. A test result shows that by adopting the method provided by the invention, the ash content of the obtained clean coal is less than or equal to 14wt.%, and the ash content of tailings is more than or equal to 63wt.%.

Description

technical field [0001] The invention belongs to the technical field of solid waste recycling and treatment, and in particular relates to a method for flotation coal from coal-containing foundry dust. Background technique [0002] Coal-containing foundry dust is generated during the casting process of metal castings and collected by dust collectors. At present, the treatment methods of coal-containing foundry dust are mainly discarded, landfilled or mixed burning, and the available coal resources in coal-containing foundry dust are wasted in large quantities. Coal-containing foundry dust contains coal particles. During the casting process, the clay minerals attached to the surface of coal particles will form ettringite at high temperature, so that the coal particles are wrapped by ettringite, which cannot be removed from coal-containing foundry dust by conventional flotation. Clean coal with low ash content is obtained. [0003] Chinese patent application CN111420809A discl...

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Problems solved by technology

[0003] Chinese patent application CN111420809A discloses a flotation separation method for casting dust removal ash powder, through pretreatment first, then two flotation and filtration treatments, the separation of coal powder and aluminosilicate substances is completed, and the Resource reuse of foundry dust, but this method does not fully dissociate coal particles in coal-containing foundry dust, and the yield of clean coal with low ash content is low

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