Classifying, separating and dewatering method for high-ash-content difficultly-separated coal slime

Abstract

The invention discloses a classifying, separating and dewatering method for high-ash-content difficulty-separated coal slime. The classifying, separating and dewatering method includes: pumping a coal slime water system coal slime to a hydraulic classifying cyclone for classifying, enabling the coal slime to enter primary floatation equipment to separate by overflowing, subjecting bottom flow to entering a separating machine of a liquid-solid fluidized bed to separate, mixing and 'doping' primary floated fine clean coal and coarse-grain clean coal prior to entering a horizontal sedimentation perforated basket centrifuge to dewater and recycle, enabling filtrate and centrifugate of the horizontal sedimentation perforated basket centrifuge to enter secondary floatation equipment to separate, dewatering secondarily-separated clean coal by a quick-opening filter press, doping on-sieve products of coarse-grain tailing coal slime dewatered by a high-frequency sieve into coal products, and mixing backwater of the high-frequency sieve and primarily-separated tailing coal, the secondarily-separated tailing coal and filtrate of a clean coal quick-opening filter press into a tailing coal concentrator and the filter press to dewater and recycle. Therefore, high-quality clean coal low in ash content and water and high in recycling rate is obtained, the problem of 'loss of coarse coal' of floatation of tailing coal is solved, and the technical difficulty of high-precision separation of high-ash-content difficultly-separated coarse and fine coal slime is overcome.

Description

technical field [0001] The invention relates to a coal slime separation technology, in particular to a method suitable for high-efficiency classification, separation and dehydration of coarse and fine coal slimes in high-ash refractory coal slimes. Background technique [0002] As my country's main energy source, coal will account for about 70% of the total primary energy production and consumption for a long time to come. In order to meet the energy demand of rapid economic development, the amount of coal mining is increasing year by year, and the task of coal washing is very arduous. With the improvement of the degree of coal mining mechanization, the depth of coal mine mining continues to deepen; the characteristics of my country's coal resources are fine, miscellaneous, and difficult; The promotion of media cyclone separation equipment and technology has led to an increase in the amount of floating coal slime, higher and higher ash content, an increase in the proportion ...

AI Technical Summary

Problems solved by technology

However, this process has the following deficiencies when dealing with coarse-grained coal slime with high ash content and high-ash fine slime content: (1) It is between the lower limit of effective separation of dense medium cyclone and the upper limit of effective separation of flotation. The coarse-grained coal slime in the middle cannot be effectively separated in the dense medium cyclone, and the ash content is relatively high

(2) A large amount of high-ash fine mud enters the secondary flotation with the filtrate and centrifugate of the sedimentation filter centrifugal dehydrator, resulting in extremely fine particle size and poor floatability of the secondary flotation slime. Conventional flotation machines cannot meet the requirements of such coal. The requirements of the secondary flotation of mud, the ash content of the flotation clean coal is too high, which also leads to the "back ash" of the dense medium clean coal

The above two "back ash" phenomena seriously affect the quantity and quality of the final commercial clean coal

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