Separation technique for difficult-to-separate steam coal

Abstract

The invention discloses a separation technique applicable to difficult-to-separate steam coal, and belongs to a coal separation method. The separation technique comprises the steps that A, drying-method separation is adopted for coal with the particle sizes larger than 50 mm, middling coal is broken and then subjected to re-separation operation; B, wet-method separation is adopted for coal with the particle sizes of 13-50 mm, and middling coal is broken is subjected to re-separation operation; C, wet-method separation is adopted for coal with the particle sizes of 3-13 mm, and middling coal isbroken and subjected to re-separation operation; and D, wet-method separation is adopted for coal with the particle sizes of 1-3 mm, and coal with the particle sizes of 0-1 mm is subjected to pressing filtering operation for obtaining coal slime. Dry-method classification is adopted for raw coal; classification equipment comprises a bohou screen and an air-stream classification machine; the coalis not in contact with water before separation; the argillization degree is lowered; generation of secondary coal slime is reduced; affection of the argillization degree on the separation process is overcome; clean coal is recycled; the recycling rate of clean coal is improved, so that maximum resource utilization of steam coal is ensured; different separation modes are adopted according differentparticle sizes of coal; coarse particles are subjected to intelligent dry-separation machine separation; middle-size particles are subjected to dense-medium shallow slot separation; and fine particles is subjected to three-product dense-medium hydrocyclone separation; and while the highest separation precision is ensured, the separation cost is the lowest.

Description

technical field [0001] The invention relates to a steam coal separation process, in particular to a separation process for refractory steam coal suitable for medium coal crushing and re-selection. Background technique [0002] With the modern development of my country's coal mining industry, the continuous increase of coal mining volume, the further increase of coal consumption demand and the gradual improvement of the market's quality requirements for thermal coal products, the proportion of difficult-to-select thermal coal has increased significantly, and its coal quality is relatively low. Poor quality, serious gangue slime in raw coal, high fine mud content, poor selectability, the conventional thermal coal separation process can no longer meet the market requirements for thermal coal products, and the market price of thermal coal is low, the separation Profitability is poor, which seriously restricts the comprehensive selection of thermal coal separation process in coal p...

AI Technical Summary

Problems solved by technology

[0003] Conventional steam coal separation process, such as: dry separation process, the whole separation process does not add water, but the separation accuracy of this process is low, and only about 80% of the gangue in the raw coal can be removed, and the -6mm particle size The sorting accuracy of steam coal is extremely poor, so this part of steam coal is usually not involved in sorting, and is directly used as a product or blended. Therefore, the ash reduction rate of this process is low, and the quality of clean coal is not high. Generally, it is only suitable for easy selection, Sorting coals that are moderately selectable or difficult to select, for steam coal that is difficult to select or extremely difficult to select, the separation effect is poor; the jigging process uses water media instead of heavy media as the separation medium, although the cost The heavier medium separation process is low but the separation accuracy is not high, so it is not suitable for difficult and extremely difficult coal separation; the whole-level heavy medium separation process has high separation accuracy and strong applicability to raw coal quality, but the process The contact and convection between the material and the dense medium suspension will be intensified, which will increase the amount of secondary slime in the system, thereby indirectly increasing the cost of washing; The dense medium separation process has a low processing cost per ton of coal, and is suitable for sorting thermal coal with a large lump coal content and low ash content in the final coal. However, because the final coal is not selected, this has largely caused waste of clean coal resources. , indirectly reduces the profit per ton of coal

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