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Wedge Wire Screen for Coal Washing Wastewater Treatment

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Update time : 2021-03-25 14:19:24
Slime water treatment is an important part of the coal washery, in order to protect the environment, more and more coal washery use closed-circuit water washing. 

Characteristics of coal washing wastewater

Coal washing wastewater is a weakly alkaline colloidal system, which is characterized by a strong negative charge on the particle surface.

High concentration and CODcr; high content of fine particles; high viscosity; large specific resistance of sludge, poor filtration performance.

Treatment process

The coal washing water is first collected into the regulating tank. 

The sewage from the regulating pool is lifted by the pump, and a coagulant mixer is set on the pipeline behind the pump. Before and after the coagulant mixer, coagulant aids and coagulants are added respectively, and then it enters the purifier.

First, the clean coal is sorted out by the clean coal separation device, discharged by the equipment, and then separated by the Johnson dewatering screen to recover the clean coal

After the recovery of clean coal, the wastewater is discharged from the top of the purifier through the processes of centrifugal separation, gravity separation, dynamic check filtration, and sludge concentration, and the treated clear water is sent to the clean water tank for reuse or discharge. The concentrated coal sludge discharged from the bottom of the purifier is discharged to the coal sludge percolation drying tank or used after being dried by the drying equipment.

Wedge wire screens are widely used in coal preparation plants for slime dewatering and recovery. After slime dewatering, impurities in the water have been reduced, the pipe will non-clogging, which helps to improve the circulate rate of wash water. While having advantages of high recovery rate, significantly ash reduction and large processing capacity.