Washing process for coal with much ash, mud and gangue

Abstract

The invention discloses a washing process for coal with much ash, mud and gangue. According to the washing process, raw coal enters an air dense medium coal picker first, so that the gangue is thrown out in advance; then, the raw coal enters a three-product dense medium cyclone, so that coarse clean coal, coarse middling coal and coarse gangue are obtained; the coarse clean coal enters a medium-removing dewatering screen, so that coarse particle clean coal is obtained; the coarse gangue enters the medium-removing dewatering screen, so that the gangue is obtained; the coarse middling coal is subjected to reselection and floatation, so that fine particle clean coal, final clean coal and coal slime are obtained. A second-level flotation column is used during floatation, so that floatation efficiency and the flotation recovery rate are both high.

Description

technical field [0001] The invention relates to a separation process of coal slime, in particular, it is suitable for the separation process of difficult coal slime with high ash, high mud and high gangue. Background technique [0002] With the over-exploitation of coal in our country for many years, high-quality coal resources are becoming less and less, and lean coal mines that were difficult to mine and recover in the past have now become mine sources that must be faced. Most of these lean coal mines have high ash, High mud, high gangue rate, poor selectability and other aspects. Among them, the content of -200 mesh fine coal increases, resulting in the high ash content of flotation clean coal often due to the entrainment of high ash and fine mud, and the coarse-grained joints also interfere with the flotation process, and the ash content of joint minerals is generally close to the ash content of raw coal , the proportion accounts for about 20% of the raw coal. If the co...

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Problems solved by technology

This process is mainly suitable for the separation of conventional easy-to-separate coal slime, and is widely used in my country. However, for high-ash, high-mud, and high-sludge difficult-to-separate coal slime, this process has the defects of low product recovery and production efficiency, and it is difficult to solve the problem of high ash. The influence of fine mud entrainment and associated minerals on the flotation process, so the development of key technologies for high-efficiency separation of high-ash refractory coal slime and high gangue ratio has become a problem that needs to be solved urgently in the process of efficient and clean utilization of coal resources

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