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.