Lignite separation process

Abstract

The invention relates to a lignite separation process, and belongs to coal washing methods. The lignite separation process comprises the following steps of: desliming broken lignite; putting obtained screen underflows into size mixing equipment to perform size mixing; outputting obtained waste rocks, crushing obtained middling coal in a crusher, putting the crushed middling coal into an ore grinding machine, putting a product after ore grinding into the size mixing equipment to perform size mixing, putting obtained cleaned coal into a sieve bend and a grading and dewatering screen for dewatering and grading, and putting screening water into a cleaned coal thickener; outputting lumpish cleaned coal obtained by the grading and dewatering screen, and putting fine cleaned coal into a centrifuge for dewatering again; outputting low-water fine cleaned coal obtained by the centrifuge, and putting centrifugate into the cleaned coal thickener; putting foams obtained through reverse flotation into a coal slime pressure filter for pressure filtering, and putting underflow into the cleaned coal thickener for thickening; putting filtrate obtained by the coal slime press filter into a circulating pool, and outputting filter cakes as coal slimes; putting overflow of the thickener into the circulating pool, and putting the underflow into a cleaned coal pressure filter for pressure filtering; and putting the filtrate into the circulating pool. The lignite separation process integrates desliming, jigging, dewatering, regrinding of the middling coal, reverse floating and coal slime water purifying, and is concise, low in investment and operation cost, and high in economic benefit.

Description

technical field [0001] The invention relates to a coal washing method, in particular to a lignite sorting process. Background technique [0002] With the depletion of high-quality coal resources, lignite with abundant reserves will become one of the main energy sources in my country in the future. At present, my country's lignite is mainly used for direct combustion power generation, but for high gray lignite, its utilization efficiency is low. [0003] The characteristics of lignite are mainly manifested in the low degree of deterioration, easy weathering when exposed to air, muddying when exposed to water, and poor buoyancy. Therefore, lignite has always been considered difficult for wet separation, and the research on lignite is mainly limited to four aspects: drying, dry separation, dry distillation and pulping. For high-rank coal, wet separation can effectively reduce the ash content in coal, such as jigging gravity separation, dense medium separation, and coal slime ...

AI Technical Summary

Problems solved by technology

However, the traditional jigging separation + flotation process for lignite separation, the slime water treatment system is more complicated, the water removed by jigging products needs to be treated in the pyramid tank or Yongtian sedimentation tank first, and the water volume of jigging operation is large , the treatment effect is not ideal, and it also leads to a low concentration of the floating pulp in direct flotation, which affects the flotation index

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