Resourceful treatment system for mixed salt solution and resourceful treatment method thereof

Abstract

The invention provides a resourceful treatment system for a mixed salt solution and a resourceful treatment method. The resourceful treatment system comprises a gypsum synthesis unit, an evaporation unit and a reaction unit which are sequentially connected in the material flow direction, the resourceful treatment system further comprises a calcining unit, an ammonia distillation unit and a salting-out unit which are respectively connected with the outlet of the reaction unit, wherein an outlet of the calcining unit and an outlet of the ammonia distillation unit are combined into one path and then are connected into the reaction unit, the ammonia distillation unit is further connected with the gypsum synthesis unit, and the salting-out unit is circularly connected with the evaporation unit.The method aims at the characteristics of a mixed salt solution of sodium chloride and sodium sulfate; sodium sulfate and calcium chloride in a normal-pressure sodium chloride solution are synthesized into alpha-semi-hydrated high-strength gypsum, sodium chloride and ammonium bicarbonate react to prepare sodium carbonate, ammonium chloride is prepared through freezing salting-out in a combined-soda method, and other technologies are organically coupled, so that the sodium chloride and sodium sulfate mixed salt solution recycling system and the method are provided.

Description

technical field [0001] The invention belongs to the technical field of mixed salt solution treatment, and relates to a mixed salt solution treatment system and treatment method, in particular to a mixed salt solution resource recovery treatment system and treatment method. Background technique [0002] High-salt wastewater refers to wastewater containing organic matter and total dissolved solids with a mass fraction of at least 3.5%. In addition to containing a large amount of organic pollutants, such wastewater usually also contains Cl － , SO 4 2－ 、Na + , Ca 2 + and other soluble inorganic salt ions. The sources of high-salt wastewater are very wide: one is the high-salt wastewater generated during the direct utilization of seawater, which is mainly produced in coastal cities where seawater is used as production water or cooling water for industries such as electric power, chemical industry, and machinery; It is the high-salt wastewater produced in the process of che...

AI Technical Summary

Problems solved by technology

However, with the requirement of zero discharge of waste water in many industries, a large amount of sodium chloride and sodium sulfate will inevitably be produced and cannot be used, and most of them can only be stored

The biggest outlet for sodium chloride is the chlor-alkali and soda ash industry. Among them, the chlor-alkali industry uses ion-exchange membrane electrolysis, which has extremely high requirements for sodium chloride. It is difficult to use the above-mentioned waste water evaporation and waste salt as raw materials, while the soda ash industry has a large scale and is located in coastal areas or Requires a huge amount of synthetic ammonia, limited use

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