Treatment method and device for coal chemical industry high-concentration brine

Abstract

The invention discloses a treatment method and device for coal chemical industry high-concentration brine. The treatment method for the coal chemical industry high-concentration brine includes the following steps that 1, preheating and evaporating concentration are conducted on the coal chemical industry high-concentration brine in sequence; 2, sodium sulfate crystallization is carried out on the high-concentration brine concentrated in an evaporation mode to obtain sodium sulfate slurry and mother liquor, and the sodium sulfate slurry is thickened, treated in a crystal growth mode and centrifugally separated to obtain sodium sulfate crystal; 3, sodium chloride crystallization is carried out on the mother liquor obtained in the step 2 to obtain sodium chloride slurry and mother liquor, and the sodium chloride slurry is thickened, treated in a crystal growth mode and centrifugally separated to obtain sodium chloride crystal; 4, sodium nitrate crystallization is carried out on the mother liquor obtained in the step 3 to obtain sodium nitrate slurry and mother liquor, and the sodium nitrate slurry is centrifugally separated to obtain sodium nitrate crystal. Zero emission of the coal chemical industry high-concentration brine and resource utilization of crystalline salt are achieved.

Description

technical field [0001] The invention relates to the technical field of water treatment, in particular to a coal chemical high-concentration brine treatment method and equipment for realizing zero discharge and resource utilization of crystalline salt. Background technique [0002] High-salt wastewater refers to wastewater with a total salt content of at least 1%. It comes from a wide range of sources, mainly in industries such as electric power, oil refining, chemical industry, metallurgy, papermaking, and pesticides. Among them, the high-concentration salt wastewater in the coal chemical industry mainly comes from the coal gas washing wastewater in the production process, the drainage of the circulating water system, and the drainage of chemical water stations. It is characterized by high salt content, mostly Cl - , SO 4 2- 、Na + The pollutants are mainly total salt content (TDS). The density of this high-salt wastewater is high, and the activated sludge is easy to float...

AI Technical Summary

Problems solved by technology

[0008] For some coal chemical companies, when the treatment effect of the front-end biochemical system is not ideal, the nitrate content in the high-concentration brine is relatively high, but the separation of sodium chloride and sodium sulfate has not finally achieved zero discharge of high-concentration brine. and poor assurance of sodium chloride and sodium sulfate purity

Therefore, it is urgent to find a process technology that can crystallize sodium chloride, sodium sulfate, and sodium nitrate in high-concentration brine respectively to achieve industrial grade products, and finally realize the resource utilization of crystallized salt and zero discharge of waste water, so as to solve the problem of biochemical treatment The problem of zero discharge of wastewater from unsatisfactory coal chemical enterprises

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