Flip-flow screen dry fine coal removal dense medium separation method of lump coal before feed for washing

Abstract

The invention relates to a flip-flow screen dry fine coal removal dense medium separation method of lump coal before feed for washing. After raw coal is classified through a phi 13 mm flip-flow screen, pulverized coal with a particle size of being less than 13 mm enters a pulverized coal cabin or a pulverized coal washing system. The lump coal with the particle size of being greater than 13 mm enters the phi 13 mm lump coal flip-flow screen to remove fine coal, an oversize after fine coal removal of the lump coal flip-flow screen enters a dense medium shallow groove sorter, and undersize enters the pulverized coal cabin; after a dense medium shallow groove separator overflow is dehydrated and medium-removed by a wash lump medium removal screen, the overflow enters a phi 25 mm wash lump classification screen to be classified into small wash lumps and big wash lumps; an underflow of the dense medium shallow groove separator is dehydrated and medium-removed by a waste rock medium removal screen to form blocky waste rock; the undersize of the medium removal screen is divided into two parts; after an after-screen section enters a composite medium bucket for continuous use and an before-screen section enters a rare medium bucket, the medium is pumped into a magnetic separator to recover the medium; tailings of the magnetic separator enter a slime water treatment system. The slime content produced by lump coal washing is reduced, the product recovery rate is improved and the lump coal product undersize fraction is reduced.

Description

technical field [0001] The invention relates to the field of coal separation, and relates to a lump coal dry depowder separation process. Background technique [0002] Coal is the main energy source in our country and has always occupied a dominant position in primary energy production and consumption. In order to meet the requirements of rapid economic development, the amount of coal mining in my country has increased year by year, and the task of coal washing is very arduous. With the improvement of the degree of mechanization of coal mining and the moderate deepening of mining, the characteristics of "poor, miscellaneous and difficult" coal itself in my country have increased the amount of raw coal slime in the coal preparation plant, and the selectivity has deteriorated. Processing presents great challenges. At present, the dense medium separation process has become the mainstream process in coal preparation plants because of its high separation accuracy, stable quality...

AI Technical Summary

Problems solved by technology

The mainstream separation equipment used for lump coal includes dense medium shallow tank separator, inclined wheel, vertical wheel separator and jig machine. Generally, the desliming process before selection is adopted, but the desliming process is due to the impact of water spray on the coal adhered to the coal. The coal slime washing effect on the surface of the grain, on the one hand, the process is complicated and the equipment is more, on the other hand, the follow-up slime treatment is troublesome, the required equipment is large, and the investment is large

[0004] At present, the mainstream desliming screens mainly include vibrating screens, banana screens and string screens. According to the results of on-site production practice, they have a common problem: low screening efficiency, easy wear of the screen surface, and easy blockage of the screen holes. At the same time, on the one hand, it needs to enter the coal slime water system for processing under the desliming screen, which increases the capacity and equipment of the coal slime water system; on the other hand, there is a lot of coal slime, the recovered product has high moisture content, and the product recovery rate is low. , large loss, low economic benefit

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