A process for directly preparing coal-water slurry from the underflow of the thickener in a coal preparation plant

Abstract

The invention discloses a process for directly preparing coal water slurry from underflow of a concentrator of a coal preparation plant. The process comprises three working procedures of preparing raw materials, blending the coal water slurry and conveying a finished product; floatation tailings are concentrated by the concentrator; the underflow of the concentrator is not subjected to pressure filtration dehydration treatment and is directly fed into a hydrocyclone group for classifying; qualified fine materials are fed into a coal slurry mixing tank; a certain proportion of fine pulverized coal and a proper amount of dispersant and stabilizer are proportioned in the coal slurry mixing tank according to the feeding amount of the materials and the requirement on the quality of the coal water slurry; the substances are sufficiently and uniformly mixed and stirred to prepare a slime coal water slurry product with good flowability and stability and can be provided for a nearby industrial kiln for burning. According to the process disclosed by the invention, the pressure filtration working procedures in the treatment process of the floatation tailings can be reduced, the treatment process of the tailings is simplified, and the operation cost of the coal preparation plant is reduced; in addition, the dispersion difficulty caused by agglomeration of filter cakes in the process of preparing the coal water slurry from the coal slime subjected to pressure filtration can be reduced, the wear of the equipment is reduced, and further the production cost of the slime coal water slurry is reduced.

Description

technical field [0001] The invention relates to a process for directly preparing coal-water slurry from the underflow of a thickener in a coal preparation plant, and belongs to the field of coal washing, processing and clean utilization. Background technique [0002] Coal washing is not only an effective and important method to improve coal quality, but also the most economical and effective technical approach to reduce coal pollution and improve the ecological environment. Flotation tailings (coal slime) are the main by-products of coal preparation plants. They have the characteristics of high moisture content, fine particle size, high particle content, high ash content and high viscosity, which brings a lot of inconvenience to comprehensive utilization. With the improvement of environmental protection awareness and coal quality requirements, the coal slime in coal washing plants is often unsalable. According to statistics, the current national annual discharge of coal sli...

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Problems solved by technology

[0007] The purpose of the present invention is aimed at the existing coal slime coal-water slurry production process in which the coal slime is firstly dewatered by press filtration, and then added a large amount of water to disperse in the subsequent pulping process, the process is complex, the energy consumption is high and the coal slime after press filtration The filter cake is easy to agglomerate into blocks, which makes it difficult to disperse, and the flocculant in the thickener is not fully utilized. A process for preparing coal-water slurry directly from the underflow of the thickener in the coal preparation plant is proposed without being dewatered by pressure filtration.

The invention can not only simplify the treatment process of flotation tailings in existing coal preparation plants, reduce the production cost of coal slurry, but also effectively solve the problems of land occupation and environmental pollution caused by coal slime stacking in coal preparation plants ; Ultimately realize the high value-added utilization of coal slime and increase the economic benefits of the enterprise

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