A method for producing concentrated brine from sea salt

Abstract

The invention provides a brine concentration method for sea salt production and belongs to the technical field of sea salt production. The method comprises steps as follows: seawater enters a pretreatment device for removal of impurities and enters a nanofiltration device for removal of divalent ions, nanofiltration producing water enters a multi-stage high-pressure reverse osmosis device for highconcentration, and high-concentration saline water is prepared; part of high-pressure reverse osmosis producing water is subjected to low-pressure reverse osmosis for preparation of pure water, and the other part of water flows back to a seawater desalting plant. The multi-stage high-pressure reverse osmosis device is formed through series connection of high-pressure reverse osmosis membrane groups in a form of continuous section groups, producing water of each section of the high-pressure reverse osmosis membrane groups flows back for use or enters a pure water preparation process, concentrated water of each section of the high-pressure reverse osmosis membrane groups enters the downstream high-pressure reverse osmosis membrane groups, the purpose of high concentration is finally achieved through continuous series connection, and strong brine is prepared. According to the method, more efficient concentration is realized, factory brine preparation is realized, the tedding area for salt making is greatly reduced, graded reuse of producing water is realized, utilization efficiency of the producing water is improved, and treatment cost is reduced.

Description

technical field [0001] The invention relates to the technical field of sea salt production, in particular to a method for producing concentrated brine from sea salt. Background technique [0002] With the development of my country's seawater desalination industry, the treatment of concentrated seawater after desalination has become an urgent problem to be solved. The direct discharge of concentrated seawater will have a certain impact on marine organisms and the marine environment, especially for my country's inland Bohai Sea, where seawater exchange capacity is poor, and direct discharge of concentrated seawater into the sea will cause ecological pollution, which limits the development of seawater desalination industry in the Bohai Rim region. Further development. For the salt industry, it is facing the challenge of the depletion of underground brine resources and the shrinking of salt fields; the concentration of concentrated seawater is about twice that of seawater, which...

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Problems solved by technology

[0003] Traditional sea salt production is realized through tanning in salt fields, which covers a large area, is seriously affected by climate, and has a long salt production cycle. However, factory concentrated salt production saves land area and improves labor productivity, which is an inevitable choice for the development of salt production enterprises.

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