Efficient crushing and three-section type screening method of coking coal gravity middings

Abstract

An efficient crushing and three-section type screening method of coking coal gravity middings belongs to coal crushing, dissociating and screening processes. Gravity middings in a coking coal preparation plant are taken as a raw material to be crushed through rolling to the fraction being below 6 mm or 3 mm; a desliming screen is used to deslime a material with the fraction being 1 mm, a material with the fraction being 6 to 1 mm or 3 to 1 mm enters into a three-product dense medium cyclone, and clean coal, middings and gangues are respectively obtained after two sections are subjected to medium drainage; the material with the fraction being 1 mm is mixed with tailings in a clean coal magnetic separator, fine coal slimes with the fraction being 0.25 mm are deslimed by a classifying cyclone; coarse coal slimes with the fractions being 1 to 0.25 mm enter into a teetered bed separator for screening, light products are dewatered by a sieve bend and a coal slime centrifuge to obtain coarse clean coal, and heavy products are dewatered by a screen bowl centrifuge to obtain tailings; the fine coal slimes with the fractions being 0.25 mm enter into a flotation machine for flotation, and foamed clean coal and the tailings are sequentially subjected to concentration and pressure filtration dewatering to obtain flotation clean coal and the tailing product; and after the gravity middings are crushed through rolling, the product returns to a mixing barrel. The method has the advantages that the graded screening is carried out on the preselected coal slimes with coarse fraction and fine fraction, and the equipment screening precision is improved.

Description

technical field [0001] The invention relates to a coal crushing, dissociation and separation process, in particular to a high-efficiency crushing and three-stage separation method for heavy separation of coking coal. Background technique [0002] my country has abundant reserves of coal resources and a complete range of coal types, but the resources of coking coal are relatively scarce, accounting for about 27.6%. Among them, fat coal, coking coal and lean coal account for 3.75%, 6.71% and 4.17% of the total coal resources respectively. At present, coking coal and fat coal resources, which are indispensable for the coking industry, have become scarce resources, and their mining, processing and utilization have been protected by national policies or energy strategies. The recovery efficiency of scarce resources is low, and there is an urgent need for a reasonable and efficient separation and recovery process for coking coal. Contents of the invention [0003] The purpose ...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a high-efficiency crushing and three-stage separation method for coking coal gravity separation, so as to solve the problem of low recovery rate of existing scarce coking coal

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