Method for sequentially extracting chemical components in seawater

Abstract

The invention discloses a method for sequentially extracting chemical components in seawater. The method comprises the following steps: (1) removing carbonates in the seawater; (2) extracting Mg<2+> and Ca<2+> in the seawater to generate Mg(OH)2, CaSO4 and CaCO3 products; (3) concentrating and crystallizing to obtain NaCl; (4) extracting the crystallized KCl; (5) extracting bromine; (6) extracting boron in concentrated brine in the form of a boric acid precipitate, and extracting fluorine ions in the form of CaF2; and (7) when the LiCl in the concentrated brine is approximate to the saturated state, adding soda ash into the concentrated brine so as to crystallize and separate out LiCl in the form of Li2CO3. A condensation-type turbogenerator unit electricity-water-salt cogeneration technique is utilized to sequentially extract the chemical components in the seawater to implement seawater comprehensive utilization, thereby generating Mg(OH)2 (which can be converted into MgO), CaSO4, CaCO3, NaCl, KCl, bromine, CaF2 and other products.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for classifying and proposing chemical components in seawater. Background technique [0002] Seawater (or brine) contains a large amount of NaCl, KCl, Ca 2+ , Mg 2+ 、Br - , F - , and other chemical substances, but the current use of seawater is only desalination to produce fresh water, the use of brine is mainly to produce NaCl through exposure, and there are also brine produced after salt production to produce magnesium oxide, extract KCl, and extract bromine, etc. Seawater (or brine) is comprehensively utilized to classify and propose various chemical components. [0003] At present, the main method of proposing bromine is to propose from the brine mother liquor after producing salt. The process is more complicated and the pollution is heavy. for difficulty) [0004] At present, the production of NaF mainly uses fluorite ore or waste gas from phosphate fertilizer...

AI Technical Summary

Problems solved by technology

[0003] At present, the main method of proposing bromine is to propose from the brine mother liquor after producing salt. The process is more complicated and the pollution is heavy. for difficulty)

[0004] At present, the production of NaF mainly uses fluorite ore or waste gas from phosphate fertilizer plants as raw materials, and does not use seawater (or brine) as raw materials to produce NaF, and the former has more complicated processes, heavier pollution, and higher energy consumption.

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