About the recovery of fine coal which above 200 mesh (0.074mm) in coal water, the focus needs to analyze the characteristics of coal water. For the coal washing plant with a large amount of coal slime, filter press load, fine coal powder hardly to screening and recycling problem, it need to find a reasonable solution.

The main parameters of slime water are the concentration, viscosity, ash, chemical properties and coal particle size, which are composed of coal and water. When the slime water concentration is less than 20%, the fine coal powder is diluted in the slime water, suspended in the water state, with the screen surface contact time is short, most of the fine coal powder has not settled to the underwater and contact the screen surface,then just out of the coal screening machine.

As the slime particle size becomes thinner, the relative motion of the particles will increase, the viscosity of the slime water increases, the repulsive effect of the surface charge between the particles becomes apparent, and the slime water has some colloidal properties, which leads to fine coal powder is difficult to separate from the slime water, resulting in high-frequency coal screening machine and the same flow of coal water, less recovery.

According to the above characteristics can try the following program: First, the layout of concentrated cyclone, increase the concentration of slime water, and then transported to the 5-layer high-frequency fine coal screening machine, the laminated is equivalent to an increase in the large screening area, lengthened fine coal powder to sink to the underwater and contact time with the sieve plate, while the configuration of high quality, high opening rate to prevent wear-resistant polyurethane screen plate to improve the handling capacity.