System and method for extracting and recovering fine coal slime from coal slime

Abstract

The invention discloses a system and a method for extracting and recovering fine coal slime from coal slime. The system comprises a classification cyclone, a coarse coal slime sorting system, a first-stage concentrator, a second-stage concentrator, a dewatering device, a laminated screen and a dewatering and drying device; and the method comprises the following steps (1) system coal slime water isclassified through the classification cyclone; (2) classified overflow is settled and classified through the first-stage concentrator; (3) the coal slime is subjected to secondary grading through thelaminated screen; (4) screen residues are dewatered and dried to obtain the fine coal slime; and (5) the high-ash fine coal slime is subjected to overflow flocculation sedimentation separation so asto obtain the discharged coal slime. The system and the method have the advantages of low investment, high efficiency, simple process and good economic benefits. If 6 million tons of raw coal is washed annually, after the fine coal slime is recovered according to the method, the discharged coal slime is about 600-650 thousand tons, and the recovered low-ash coarse particle fine coal slime is about350-400 thousand tons, the resource waste is greatly reduced, the resource utilization rate is improved, and meanwhile, the amount of waste coal slime is greatly reduced.

Description

[0001] Technical field: [0002] The invention relates to a system and method for purifying and recovering clean coal slime, in particular to a system and method for purifying and recovering clean coal slime from coal slime. [0003] Background technique: [0004] Coal slime treatment is one of the most important links in thermal coal preparation plants. Most of the coal slime treatment methods in the existing steam coal preparation plants are to settle and concentrate the slime water through a thickener, then dehydrate it through a plate and frame filter press, and then directly discharge it outside. This kind of coal slime treatment method has serious hidden dangers in the later stage of environmental protection: firstly, the dust in the coal slime stacking site will pollute the surrounding atmosphere, secondly, the coal slime water will infiltrate and pollute the local groundwater, and finally the coal slime itself will be discharged as solid waste. Vegetation damage on sit...

AI Technical Summary

Problems solved by technology

This kind of coal slime treatment method has serious hidden dangers in the later stage of environmental protection: firstly, the dust in the coal slime stacking site will pollute the surrounding atmosphere, secondly, the coal slime water will infiltrate and pollute the local groundwater, and finally the coal slime itself will be discharged as solid waste. Vegetation damage on site

In addition, in the coal slime discharged by this slime treatment method, the low-ash coarse-grained slime with a particle size greater than 0.075mm and an ash content less than 35% accounts for about 35-40% of the discharged coal slime. Coal slime can be completely recycled and used as fuel for power plants. However, due to the defects in the processing method of raw coal slime, this part of low-ash coarse-grained coal slime is completely discharged as washing waste. About 1 million tons of coal slime are discharged after dehydration by the filter press, of which about 350,000 to 400,000 tons of low-ash coarse-grained coal slime can be recovered, which is a serious waste of resources

Images