Process for washing and selecting high-ash, high-water easily-argillized lignite

Abstract

The invention relates to a process for washing and selecting high-ash, high-water easily-argillized lignite. The process comprises the following steps of: manually argillizing gangue in the lignite by using argillization equipment; then screening and grading argillized raw coals according to particle sizes of 50 mm and 0.5 mm, putting the raw coals with the particle sizes of more than 50 mm into a heavy-medium shallow trench system for washing and selecting, and obtaining large clean coals and gangue products; and putting the raw coals with the particle sizes of 50 mm and 0.5 mm into a jigging system for washing and selecting, and obtaining clean coals and gangue products, wherein coal slime with the particle size of -0.5 mm is mainly formed by argillizing the gangue, has high ash content, and can be directly discharged into a tailing base for depositing and cleaning; coal slime water formed during washing and selecting by the heavy-medium system and the jigging system enters a concentrator for clarifying and depositing; a polycoagulant and a flocculant are added into the concentrator; overflow of the concentrator is used as circulation water for the heavy-medium system and the jigging system; bottom flow is discharged to the tailing base; and clarified water in the tailing base can be used by the argillization equipment. The cost is saved, and the washing and selecting precision is improved; and furthermore, a coal slime water treatment process is simple, and the problems that the lignite is easy to argillize, and cannot be washed and selected in water are solved effectively.

Description

technical field [0001] The invention relates to a coal preparation process, in particular to a washing process for high-ash, high-water and easy-mud lignite. Background technique [0002] my country's lignite reserves are abundant, accounting for about 12.7% of the country's total coal reserves. Lignite has high chemical reactivity and has a wide range of applications. However, the ash content of lignite in my country is generally 20%~50%, and the total moisture is generally 20%~50%. High ash and high water have become important factors that restrict further processing and utilization of lignite into high value-added products. [0003] The washing and processing of lignite has its particularity. From the perspective of on-site production, it is more suitable to wash lignite with a high degree of metamorphism, and its products can be used not only for power plants, but also for power coal in other industries. However, for lignite with high ash and high water that is easy t...

AI Technical Summary

Problems solved by technology

However, for lignite with high ash and high water that is easy to muddy, the amount of primary slime is large, and gangue is easy to muddy when exposed to water. Traditionally, washing with water as the medium can easily lead to high washing water concentration and large slime water treatment system, resulting in production The viscosity of circulating water increases rapidly, which affects the separation process, making it very difficult to recover coal slime, wash water purification and closed-circuit circulation, and greatly increase the investment and processing costs of coal preparation plants.

Therefore, in the traditional concept, it is inappropriate to wash high-ash, high-water and easy-to-mud lignite by water, such as washing will increase a lot of processing costs, and the increased sales revenue compared with raw coal is not enough to offset the processing costs

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