RECOVERING LITHIUM FROM AQUEOUS SOLUTIONS Russian patent published in 2012 - IPC C02F1/469 B01D61/46 

FIELD: chemistry.

SUBSTANCE: invention relates to recovery of lithium from aqueous solutions such as feed streams used in production of lithium-ion batteries, or formed when extracting lithium from ore-based materials. The method of recovering lithium as lithium hydroxide is realised by feeding an aqueous stream containing lithium ions into a bipolar electrodialysis cell, where the cell forms lithium hydroxide solution. The method is realised in an apparatus having a bipolar electrodialysis cell, where said bipolar electrodialysis cell includes (a) an anion-permeable membrane which enables passage of negatively charged ions but hinders passage of positively charged lithium ions; (b) a cation-permeable membrane which enables passage of positively charged lithium ions but hinders passage of negatively charged ions; (c) a bipolar membrane lying between the anion-permeable membrane and the cation-permeable membrane, which forms separate chambers with an anion-permeable membrane and a cation-permeable membrane, respectively; (d) an anode and a cathode with said anion-permeable membrane, cation-permeable membrane and bipolar membrane lying in between, and (e) direct current fed through electrodes.

EFFECT: invention enables to obtain lithium hydroxide in form of a pure product.

37 cl, 7 dwg, 4 tbl, 12 ex