The main task of the coal preparation, is to reduce the ash content of coal, is mixed in the coal gangue, coal gangue symbiosis of thick coal seam with pure coal, according to their density, shape and other physical properties differences to separate them.Coal preparation method has many kinds, generally can be divided into two broad categories.Coal preparation, the use of water or suspension is called wet coal preparation.Corresponding to the wet coal preparation is dry coal preparation.
In order to more detail shows the characteristics of the coal preparation process, the coal preparation methods are divided into the following kinds:
(1) pickingHand picking righteousness of manual picking, namely according to the coal and waste rock block in color, luster and the difference of shape for sorting.This coal preparation method implemented by artificial fully, and can only pick from the coal in addition to the particle size in 50 mm (must be at least 25 mm) above the large pieces of waste rock.Hand sorting waste rock are usually on the adhesive tape transportation machine.
(2) gravity coal preparation methodOn the basis of different density of coal and waste rock is coal preparation method.Coal and waste rock in gravity separation in the coal washer, can be concluded that coal and waste rock two kind of product.But in order to obtain good quality plant and more pure waste rock, usually in the production and produce a kind of between the plant and the coal gangue.In water or suspension gravity coal preparation process, commonly known as coal washing.Wet coal preparation, gravity can be further subdivided into: jigging, flow tank (tank), shaking table to choose, heavy medium, etc.With the aid of wind gravity separation, namely wind coal preparation method of dry coal preparation ().Rarely used in the industry, only suitable for arid area of low coal moisture easily.
(3) flotationIs, which is based on the difference of coal grains and waste rock particles...