High-alkalinity strong brine zero-discharge treatment method and system

Abstract

The invention discloses a high-alkalinity strong brine zero-discharge treatment method and system. The high-alkalinity strong brine zero-discharge treatment method comprises the steps of: S1, enabling strong brine to be subjected to preheating treatment and evaporation concentration treatment, and obtaining a concentrated solution; S2, performing sodium carbonate monohydrate evaporative crystallization treatment on the concentrated solution to obtain a sodium carbonate monohydrate mother solution and a sodium carbonate monohydrate product salt; S3, performing freezing crystallization treatment and hot melting treatment on the sodium carbonate monohydrate mother liquor to obtain frozen mother liquor and sodium carbonate monohydrate slurry; and S4, performing sodium chloride evaporative crystallization treatment on the frozen mother liquor to obtain sodium chloride mother liquor and sodium chloride product salt. Evaporation concentration, sodium carbonate monohydrate evaporation crystallization, sodium carbonate decahydrate freezing crystallization and sodium chloride evaporation crystallization treatment are sequentially carried out on the high-alkalinity strong brine, then the strong brine is recycled, sodium carbonate monohydrate and sodium chloride meeting the national standard are obtained, the water recovery rate of waste water is increased, the environment is protected, the crystalline salt is recycled, and the goal of zero emission of the strong brine is achieved.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a zero-discharge treatment method and system for concentrated brine with high alkalinity. Background technique [0002] In the production process of coal chemical industry, petrochemical industry, papermaking, metallurgy, mining and other industries, a large amount of waste water such as process system drainage, circulating water sewage, and underground water gushing in the mining process are produced, and the waste water is treated with biochemical treatment, chemical dosing treatment and membrane treatment And other conventional processing technologies, only 75%-85% of the product water can be recovered from it, and the remaining waste water is discharged with high-salt concentrated brine, polluting the surrounding water sources and the ecological environment. [0003] Due to the difference in the production characteristics of various industries produced by concent...

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Problems solved by technology

However, in the production process of some industries, the concentrated brine produced is mainly sodium carbonate and sodium chloride. The existing zero discharge process can only remove scaling factors through pretreatment and membrane concentration to achieve concentration reduction, but evaporation Crystallization is difficult to realize the resource utilization of crystallized salt, so the goal of all wastewater reuse cannot be achieved

[0004] For the zero-discharge treatment of concentrated brine, the zero-discharge treatment processes and systems currently used at home and abroad fail to treat differently or comprehensively consider the characteristics of wastewater in various industries, and cannot realize the technical problems of sodium carbonate and sodium chloride type concentrated brine reuse treatment. Therefore, it is urgent to find a treatment process and system for separating and extracting sodium carbonate and sodium chloride in concentrated brine, so as to achieve the goal of zero discharge of wastewater

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