Coal gasification ash water treatment process and equipment

Abstract

The invention relates to a coal gasification ash water treatment process and equipment. Firstly, black water generated by coal gasification firstly enters a settling tank for coarse separation to achieve the purpose of removing most suspended matter, and clear liquid of the settling tank is pumped to electric flocculation integrated equipment by using an ash water pump for fine separation. Al<3+>or Fe<2+> obtained by ionizing of an iron plate or an aluminum plate and OH<-> generated by a cathode plate are complexed to generate a high-activity hydroxyl complex, suspended matter and calcium andmagnesium ions in the ash water are subjected to hardness removal treatment, meanwhile, the suspended matter in clarified liquid can be removed, the removal rate of the calcium and magnesium ions inthe ash water passing through the electric flocculation integrated equipment can reach 70% or above, and the removal rate of the suspended matter can reach 99% or more. Due to the fact that the waterquality of the ash water passing through the electric flocculation integrated equipment is improved, on one hand, the amount of discharged ash water can be reduced, and on the other hand, due to the fact that the hardness and the suspended matter of the ash water returned to the system are reduced, the risk of scaling of the equipment and pipelines can be reduced, and the operation safety of the device is improved.

Description

technical field [0001] The invention relates to a process and equipment for treating coal gasification ash water. Background technique [0002] After the black water discharged from the coal gasification unit needs to be separated from the suspended solids and solid particles, a part of the gray water will enter the wastewater treatment plant of the whole plant as the effluent wastewater, and the other part of the gray water will be returned to the system for reuse. The level of sedimentation and separation effects directly affects the amount of external drainage and the water quality returned to the system. If the settlement and separation effect is good, the external drainage volume will be small, and the grey water returned to the system will be of good quality, which can prolong the stable operation period of the device; Poor water quality increases the risk of fouling of lines and equipment. [0003] CN201710160557.5 discloses a treatment method for electrochemically ...

AI Technical Summary

Problems solved by technology

In addition, the calcium and magnesium ions in the gray water were not removed in the settling tank, and the total hardness in the gray water was not effectively reduced

Therefore, this method leads to a large amount of clarified liquid outflow from the settling tank, and the gray water returned to the system increases the risk of fouling of equipment and pipelines due to the influence of calcium and magnesium ions

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