Method of extracting lithium with high purity from lithium bearing solution by electrolysis

摘要

The present invention relates to a method of extracting lithium with high purity from a lithium bearing solution by electrolysis. More specifically, the present invention provides a method of economical extraction of lithium from the lithium bearing solution by adding a phosphorous supplying material to the solution to prepare a lithium phosphate aqueous solution subject to electrolysis.

主权项

1. A method of extracting high purity lithium from a lithium bearing solution by electrolysis comprising the steps of:
preparing a lithium phosphate aqueous solution from the lithium bearing solution by adding a phosphorous supplying material; and extracting lithium from the lithium phosphate aqueous solution by electrolysis using an electrolytic device comprising an anode and a cathode separated from the anode by a cation exchange membrane, wherein the step of preparing a lithium phosphate aqueous solution from the lithium bearing solution by adding a phosphorous supplying material comprises the steps of: removing impurities comprising a step of adding an alkali in the lithium bearing solution to extract magnesium, boron or a mixture thereof and a step of adding an alkali, a carbonate or a mixture thereof in the lithium bearing solution from which magnesium and boron are extracted to extract calcium; extracting lithium phosphate by adding a phosphorous supplying material to the solution to precipitate lithium phosphate from the dissolved lithium; and preparing the lithium phosphate aqueous solution by dissolving the lithium phosphate in a phosphoric acid.