US 12,351,475 B2
System for producing magnesium chloride aqueous solution and system for producing magnesium
Yoshiaki Ito, Tokyo (JP); Kazuhisa Takeuchi, Tokyo (JP); and Masashi Kiyosawa, Yokohama (JP)
Assigned to MITSUBISHI HEAVY INDUSTRIES, LTD., Tokyo (JP)
Appl. No. 17/790,639
Filed by MITSUBISHI HEAVY INDUSTRIES, LTD., Tokyo (JP)
PCT Filed Dec. 14, 2020, PCT No. PCT/JP2020/046592
§ 371(c)(1), (2) Date Jul. 1, 2022,
PCT Pub. No. WO2021/140840, PCT Pub. Date Jul. 15, 2021.
Claims priority of application No. 2020-001483 (JP), filed on Jan. 8, 2020.
Prior Publication US 2023/0030186 A1, Feb. 2, 2023
Int. Cl. C25C 3/04 (2006.01); C01F 5/32 (2006.01); C01F 5/34 (2006.01)
CPC C01F 5/34 (2013.01) [C01F 5/32 (2013.01); C25C 3/04 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A system for producing a magnesium chloride aqueous solution comprising:
a crystallization unit;
a precipitation unit connected to the crystallization unit;
a removal unit connected to the precipitation unit;
an acid-alkali generation unit connected to the removal unit; and
a reaction unit connected to the precipitation unit,
wherein the crystallization unit crystallizes magnesium hydroxide by adding a sodium hydroxide aqueous solution to water to be treated using seawater as a raw material, and generates reaction slurry in which particles of the magnesium hydroxide are dispersed,
the precipitation unit stores the reaction slurry to precipitate the particles, and separates the reaction slurry into a recovered slurry containing the particles at a high concentration and a separated liquid containing the particles at a low concentration,
the removal unit removes divalent cations from the water to be treated or the separated liquid to generate a reaction liquid,
the acid-alkali generation unit generates a sodium hydroxide aqueous solution and hydrochloric acid from the reaction liquid,
the reaction unit adds the hydrochloric acid to the recovered slurry and generates a magnesium chloride aqueous solution, and
the acid-alkali generation unit has:
a main body section configured to generate a sodium hydroxide aqueous solution and hydrochloric acid from the reaction liquid;
a first connection unit configured to connect the main body section and the crystallization unit and supply the sodium hydroxide aqueous solution to the crystallization unit; and
a second connection unit configured to connect the main body section and the reaction unit and supply the hydrochloric acid to the reaction unit.