Method for producing lithium hydroxide
Provided is a method for producing lithium hydroxide, which can obtain lithium hydroxide from lithium sulfate with a relatively low cost. A method for producing lithium hydroxide from lithium sulfate includes: a hydroxylation step of allowing the lithium sulfate to react with barium hydroxide in a liquid to provide a lithium hydroxide solution; a barium removal step of removing barium ions in the lithium hydroxide solution using a cation exchange resin and/or a chelate resin; and a crystallization step of precipitating lithium hydroxide in the lithium hydroxide solution that has undergone the barium removal step.
1 . A method for producing lithium hydroxide from lithium sulfate, the method comprising:
a hydroxylation step of allowing the lithium sulfate to react with barium hydroxide in a liquid to provide a lithium hydroxide solution; a barium removal step of removing barium ions in the lithium hydroxide solution using a cation exchange resin and/or a chelate resin; and a crystallization step of precipitating lithium hydroxide in the lithium hydroxide solution that has undergone the barium removal step.
2 . The method for producing lithium hydroxide according to claim 1 , wherein, in the barium removal step, the lithium hydroxide solution has a pH of 9 or more when the lithium hydroxide solution is brought into contact with the cation exchange resin and/or the chelate resin.
3 . The method for producing lithium hydroxide according to claim 1 , wherein, in the barium removal step, the lithium hydroxide solution has a space velocity (SV) of 5 to 20 when the lithium hydroxide solution is passed through the cation exchange resin and/or the chelate resin.
4 . The method for producing lithium hydroxide according to claim 1 , wherein a weakly acidic cation exchange resin having carboxyl groups as functional groups is used in the barium removal step.
5 . The method for producing lithium hydroxide according to claim 1 ,
wherein the lithium sulfate is in a form of a lithium sulfate solution; and
wherein the lithium sulfate solution is obtained by a process comprising: a lithium dissolution step of dissolving lithium in roasted lithium ion secondary battery waste in water or an acidic solution to obtain a lithium dissolved solution; and a lithium concentration step of extracting lithium ions from the lithium dissolved solution with a solvent and back-extracting the lithium ions.
6 . The method for producing lithium hydroxide according to claim 5 , wherein, in the lithium concentration step, lithium is extracted into a solvent, the solvent is then scrubbed with a lithium solution, and lithium ions are back-extracted from the scrubbed solvent.
7 . The method for producing lithium hydroxide according to claim 1 , wherein the method produces lithium hydroxide used for producing lithium ion secondary batteries.
8 . The method for producing lithium hydroxide according to claim 1 , wherein, in the hydroxylating step, the barium hydroxide is in a form of a barium hydroxide solution, and the barium hydroxide solution is brought into contact with the lithium sulfate.
9 . The method for producing lithium hydroxide according to claim 8 , wherein the barium hydroxide solution is a saturated aqueous solution.
10 . The method for producing lithium hydroxide according to claim 8 , wherein, in the hydroxylating step, the barium hydroxide solution is brought into contact with the lithium sulfate at a liquid temperature of 40° C. to 100° C.
11 . A method for producing lithium hydroxide from lithium carbonate, the method comprising:
a hydroxylation step of allowing the lithium carbonate to react with calcium hydroxide in a liquid to provide a lithium hydroxide solution; a calcium removal step of removing calcium ions in the lithium hydroxide solution using a cation exchange resin and/or a chelate resin; and a crystallization step of precipitating lithium hydroxide in the lithium hydroxide solution that has undergone the calcium removal step.
12 . The method for producing lithium hydroxide according to claim 11 , wherein, in the calcium removal step, the lithium hydroxide solution has a pH of 9 or more when the lithium hydroxide solution is brought into contact with the cation exchange resin and/or the chelate resin.
13 . The method for producing lithium hydroxide according to claim 11 , wherein, in the calcium removal step, the lithium hydroxide solution has a space velocity (SV) of 5 to 20 when the lithium hydroxide solution is passed through the cation exchange resin and/or the chelate resin.
14 . The method for producing lithium hydroxide according to claim 11 , wherein a weakly acidic cation exchange resin having carboxyl groups as functional groups is used in the calcium removal step.
15 . The method for producing lithium hydroxide according to claim 11 , wherein the lithium carbonate is obtained by a process comprising: a lithium dissolution step of dissolving lithium in roasted lithium ion secondary battery waste in water or an acidic solution to obtain a lithium dissolved solution; and a lithium concentration step of concentrating lithium ions in the lithium dissolved solution.
16 . The method for producing lithium hydroxide according to claim 11 , wherein the method produces lithium hydroxide used for producing lithium ion secondary batteries.