Two-stage flotation process of coal slime with particle size less than 0.5mm

Abstract

A two-stage flotation process for coal slime with a particle size of less than 0.5mm, the steps are: the coal slime with a particle size of less than 0.5mm enters the first-stage flotation, and its tailings enter the tailings treatment process; the foamed clean coal of the first-stage flotation is passed through After dehydration by the sedimentation filter centrifuge, the coarse fine coal slime with a particle size greater than 0.045mm is recovered; the centrate and filtrate after dehydration by the sedimentation filter centrifuge enter the secondary flotation, and the tailings of the secondary flotation are collected through the pipeline. into the tailings of the first-stage flotation for treatment together; the foamed clean coal of the second-stage flotation is dehydrated by a filter press with thorough solid-liquid separation, and the fine coal slime with a particle size of less than 0.045mm is recovered, and the filtrate is reused ; The fine fine coal slime and the coarse fine coal slime are used as flotation clean coal to enter the commercial clean coal. The invention reduces the ash and moisture of the flotation clean coal, improves the yield, and especially overcomes the disadvantage of the vicious cycle of high ash fine mud in the foam product in the system.

Description

technical field [0001] The invention relates to a novel coal slime flotation process, in particular to a two-stage coal slime flotation process with a granularity less than 0.5mm suitable for wet coal preparation plants. Background technique [0002] Wet coal preparation plants account for more than 95% of the designed processing capacity of coal preparation plants in my country. Flotation is currently the most effective and most mature separation process for selecting wet coal preparation plants with particle size <0.50mm, and is an indispensable process for wet coal preparation plants, especially wet coking coal preparation plants. According to estimates, the amount of coal slime produced by flotation and separation in coal preparation plants in my country reaches about 200 million tons per year. Flotation can not only recover a large amount of high-quality clean coal, but also realize closed-circuit washing water circulation and zero discharge of industrial water in co...

AI Technical Summary

Problems solved by technology

[0003] So far, domestic wet coal preparation plants have adopted the first-stage flotation process for coal slimes with a particle size of <0.50 mm, resulting in high ash content in flotation clean coal (generally higher than the final commercial clean coal ash content of the coal preparation plant), especially foam The vicious cycle of high ash fine mud with particle size < 0.030mm in the clean coal product seriously affects the separation technical indicators and the closed-circuit washing water cycle of the coal preparation plant

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