Technique for producing refined salt from salt production waste liquid

Abstract

The present invention provides a refined salt preparation technology by using salt-making liquid waste. The technology comprises the following five steps: evaporation and concentration, mother liquor thickening, bitter salt recovery, washing and dehydration, as well as drying and packaging, and the refined salt will be finally sent to the salt storehouse. The effect of the invention is that the advanced vacuum salt-making technology and salt washing process are adopted in stead of alternative drying to produce high-quality industrial salt so as to improve the yield and quality of industrial salt. Meanwhile, the invention can also help improve the concentration of bittern that enters into the potassium-making work section to reduce the salinity and provide high-quality raw materials for the production of chemical plants; the application of the invention can save the alternative drying area, raise resource utilization rate, increase product yield and reduce the loss of chemical resources to provide a model road for comprehensive utilization of the seawater salt industry as well as the concentrated seawater salt-making after the desalination. The invention achieves organic combination between the new-type salt-making industry and the ocean chemical engineering and realizes zero-discharge of the salt-making waste liquid to make the brine resources be scientifically protected and rationally used. The invention can also protect the marine environment and gradually realize factory salt production.

Description

technical field [0001] The invention relates to a method for producing salt, in particular to a preparation process for producing refined salt by using waste liquid from salt production as a raw material. Background technique [0002] The concentration of the mother liquid (salt-making waste liquid) after seawater salt production is about 27°Be′, which contains a large amount of salt. Discharging into the sea will cause environmental pollution. It needs to be further concentrated and evolved to extract usable resources. Usually, the concentration is increased to about 30°Be′ after re-sunning. The disadvantage of this process is that the quality of the salt produced after re-sunning is low; [0003] Salt is the basic raw material for the production of caustic soda and soda ash in the "three acids and two alkalis" of the chemical industry, and its annual consumption is 60% of the salt production. With the increasing proportion of ionic membrane caustic soda, the demand for hi...

AI Technical Summary

Problems solved by technology

Usually, the concentration is increased to about 30°Be′ after re-sunning. The disadvantage of this process is that the quality of the salt produced after re-sunning is low;

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