# US 11,078,583 B2 · Processes for preparing lithium hydroxide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,583 B2 - Document ID: US11078583B2 - Status: Granted - Kind: B2 - Application number: 16/579,173 - Filed: 2019-09-23 - Published: 2020-03-19 - Granted: 2021-08-03 - Earliest claimed: 2013-03-15 - Assignees: Nemaska Lithium Inc. - Applicants: Nemaska Lithium Inc. - Inventors: Jean-François Magnan; Guy Bourassa; Gary Pearse; Peter Symons; J. David Genders - Web page: https://patentgrep.com/patent/US11078583B2 ## CPC - C25B 15/02: Process control or regulation - B01D 61/44: Ion-selective electrodialysis - B01D 61/445: {with bipolar membranes; Water splitting} - C25B 1/00: Electrolytic production of inorganic compounds or non-metals - C25B 1/01: Products - C25B 1/16: Hydroxides (by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34) - C25B 1/22: Inorganic acids - C25B 9/19: with diaphragms - C25B 9/21: two or more diaphragms - C25B 13/02: characterised by shape or form - C25B 13/04: characterised by the material - C25B 15/023: Measuring, analysing or testing during electrolytic production - C25B 15/027: Temperature - C25B 15/029: Concentration - C25B 15/031: pH - C25B 15/033: Conductivity - Y02E 60/36: Hydrogen production from non-carbon containing sources, e.g. by water electrolysis - C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract There are provided processes for preparing lithium hydroxide that comprise submitting an aqueous composition comprising a lithium compound to an electrolysis or an electrodialysis under conditions suitable for converting at least a portion of the lithium compound into lithium hydroxide. For example, the lithium compound can be lithium sulphate and the aqueous composition can be at least substantially maintained at a pH having a value of about 1 to about 4. ## Claims ### Claim 1 A process for preparing lithium hydroxide, said process comprising: submitting an aqueous composition comprising lithium sulphate to an electrolysis under conditions suitable for converting at least a portion of said lithium sulphate into lithium hydroxide; wherein during said electrolysis, said aqueous composition comprising lithium sulphate is at least substantially maintained at a pH having a value of about 1 to about 4; wherein said aqueous composition comprising lithium sulphate is prepared by a process comprising: leaching an acid roasted lithium-containing material with water so as to obtain an aqueous composition comprising Li+ and at least one metal ion, wherein said lithium-containing material is a material that has been previously reacted with H2SO4; reacting said aqueous composition comprising Li+ and said at least one metal ion with a base so as to obtain a pH of about 4.5 to about 6.5 and thereby at least partially precipitating said at least one metal ion under the form of at least one hydroxide so as to obtain a precipitate comprising said at least one hydroxide and an aqueous composition comprising Li+ and having a reduced content of said at least one metal ion, and separating said aqueous composition from said precipitate comprising said at least one hydroxide; reacting said aqueous composition comprising Li+and having said reduced content of said at least one metal ion with another base so as to obtain a pH of about 9.5 to about 11.5, thereby at least partially precipitating at least one metal ion so as to obtain a precipitate and an aqueous composition comprising Li+and having a reduced content of said at least one metal ion; seperating said aqueous composition from said precipitate; and contacting said aqueous composition comprising Li+ and having said reduced content of said at least one metal ion with an ion-exchange resin so as to at least partially remove at least one metal ion from said composition, thereby obtaining said aqueous composition comprising lithium sulphate. ### Claim 2 (depends on 1) The process of claim 1, further comprising: reacting said aqueous composition comprising Li+ and having said reduced content of said at least one metal ion with said another base and with at least one metal carbonate, thereby at least partially precipitating at least one metal ion under the form of at least one carbonate so as to obtain a precipitate comprising said at least one carbonate and an aqueous composition comprising Li+ and having a reduced content of said at least one metal ion; and separating said aqueous composition from said precipitate comprising said at least one carbonate. ### Claim 3 (depends on 1) The process of claim 1, wherein during said electrolysis, said pH is at least substantially maintained at a value of about 2 to about 4. ### Claim 4 (depends on 1) The process of claim 1, wherein during said process said aqueous composition comprising lithium hydroxide is at least substantially maintained at a concentration of lithium hydroxide of about 35 to about 70 g/L. ### Claim 5 (depends on 1) The process of claim 1, wherein during said process said aqueous composition comprising sulphuric acid is at least substantially maintained at a concentration of sulphuric acid of about 20 to about 50 g/L. ### Claim 6 (depends on 1) The process of claim 1, wherein during said process said aqueous composition comprising lithium sulphate is at least substantially maintained at a concentration of lithium sulphate of about 10 to about 20 g/L. ### Claim 7 (depends on 1) The process of claim 1, wherein during said process, temperature of said aqueous composition comprising lithium sulphate is at least substantially maintained at a value of about 20 to about 80° C. ### Claim 8 (depends on 1) The process of claim 1, wherein during said process, temperature of said aqueous composition comprising lithium sulphate is at least substantially maintained at a value of about 50 to about 60° C. ### Claim 9 (depends on 1) The process of claim 1, wherein during said process electrical current is at least substantially maintained at a density of about 400 to about 3000 A/m2. ### Claim 10 (depends on 1) The process of claim 1, wherein during said process electrical current is at least substantially maintained at a constant value. ### Claim 11 (depends on 1) The process of claim 1, wherein during said process voltage is at least substantially maintained at a constant value. ### Claim 12 (depends on 1) The process of claim 1, wherein an anolyte used during said process comprises ammonia. ### Claim 13 (depends on 1) The process of claim 1, further comprising adding ammonia in an anolyte used for said process, thereby generating an ammonium salt. ### Claim 14 (depends on 13) The process of claim 13, wherein said ammonium salt is (NH4)2SO4. ### Claim 15 A process for preparing lithium hydroxide, said process comprising: submitting an aqueous composition comprising a lithium compound to an electrolysis under conditions suitable for converting at least a portion of said lithium compound into lithium hydroxide; wherein during said electrolysis, said aqueous composition comprising said lithium compound is at least substantially maintained at a pH having a value of about 1 to about 4; wherein said aqueous composition comprising said lithium compound is prepared by a process comprising: leaching an acid roasted lithium-containing material with water so as to obtain an aqueous composition comprising Li+ and at least one metal ion; reacting said aqueous composition comprising Li+ and said at least one metal ion with a base so as to obtain a pH of about 4.5 to about 6.5 and thereby at least partially precipitating said at least one metal ion under the form of at least one hydroxide so as to obtain a precipitate comprising said at least one hydroxide and an aqueous composition comprising Li+ and having a reduced content of said at least one metal ion, and separating said aqueous composition from said precipitate comprising said at least one hydroxide; reacting said aqueous composition comprising Li+and having said reduced content of said at least one metal ion with another base so as to obtain a pH of about 9.5 to about 11.5, thereby at least partially precipitating at least one metal ion so as to obtain a precipitate and an aqueous composition comprising Li+and having a reduced content of said at least one metal ion; separating said aqueous composition from said precipitate; and contacting said aqueous composition comprising Li+ and having said reduced content of said at least one metal ion with an ion exchange resin so as to at least partially remove at least one metal ion from said composition, thereby obtaining said aqueous composition comprising said lithium compound. ### Claim 16 (depends on 15) The process of claim 15, further comprising: reacting said aqueous composition comprising Li+ and having said reduced content of said at least one metal ion with said another base and with at least one metal carbonate, thereby at least partially precipitating at least one metal ion under the form of at least one carbonate so as to obtain a precipitate comprising said at least one carbonate and an aqueous composition comprising Li+ and having a reduced content of said at least one metal ion; and separating said aqueous composition from said precipitate comprising said at least one carbonate. ### Claim 17 (depends on 15) The process of claim 15, wherein during said electrolysis, said pH is at least substantially maintained at a value of about 2 to about 4. ### Claim 18 (depends on 15) The process of claim 15, wherein said aqueous composition comprising said lithium compound comprises lithium sulphate, lithium chloride, lithium fluoride, lithium carbonate, lithium bicarbonate, lithium acetate, lithium stearate or lithium citrate.