A method for improving the recovery rate of heavy medium in coal preparation process

Abstract

The invention belongs to the field of wet coal dressing, and relates to dense medium coal dressing processes, in particular to a method for increasing the dense medium recovery rate in a coal dressing process. The method mainly comprises the following steps that raw coal is subjected to classified filtration; oversize materials obtained after classified filtration and a dense medium are subjected to shallow slot separation; slack raw coal needing to be washed after classified filtration and the dense medium are mixed and then subjected to separation whirlcone separation; magnetic separator tailings and centrifugal machine centrifugate generated in the shallow slot separation step and magnetic separator tailings and centrifugal machine centrifugate generated in the whirlcone separation step are subjected to whirling, concentrating and classifying; underflow generated in the whirling, concentrating and classifying step enters a sieve bend to be screened; and backwater of the sieve bend is subjected to magnetic separator secondary recovery. Before the method is adopted, the content of magnetite powder in backwater of the sieve bend is about 1.0 gram / litre; and after the method is adopted, the content can be reduced to 0.05 gram / litre, and medium consumption can be reduced by 10-15%.

Description

technical field [0001] The invention belongs to the field of wet coal preparation, relates to a dense medium coal preparation process, in particular to a method for increasing the recovery rate of the dense medium in the coal preparation process. Background technique [0002] Coal is the main energy source in my country. In 2015, the consumption of raw coal was about 3.7 billion tons, of which about 60% of the coal was produced through heavy medium coal preparation plants. Moreover, with the improvement of environmental protection requirements in our country, the proportion of dense medium coal preparation in coal preparation production will be higher and higher due to its high quality and high efficiency. [0003] Dense medium is a major consumable material in the production of dense medium coal preparation plants, accounting for about 15% of the processing cost. The heavy medium used in the current dense medium coal preparation plant mainly includes magnetite powder, etc....

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the problems of low recovery and utilization rate of heavy medium in the coal preparation process existing in the prior art, the present invention provides a method for improving the recovery rate of heavy medium in the coal preparation process, which mainly includes the following steps:

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