Processing method for lithium ion battery scrap
A method for processing lithium ion battery scrap includes a leaching step of leaching lithium ion battery scrap and subjecting the resulting leached solution to solid-liquid separation to obtain a first separated solution; an iron removal step of adding an oxidizing agent to the first separated solution and adjusting a pH of the first separated solution in a range of from 3.0 to 4.0, then performing solid-liquid separation and removing iron in the first separated solution to obtain a second separated solution; and an aluminum removal step of neutralizing the second separated solution to a pH range of from 4.0 to 6.0, then performing solid-liquid separation and removing aluminum in the second separated solution to obtain a third separated solution.
1. A method for processing lithium ion battery scrap, the method comprising:
a leaching step of leaching lithium ion battery scrap and subjecting the resulting leached solution to solid-liquid separation to obtain a first separated solution;
an iron removal step of adding an oxidizing agent to the first separated solution and adjusting a pH of the first separated solution in a range of from 3.0 to 4.0, then performing solid-liquid separation and removing iron in the first separated solution to obtain a second separated solution; and
an aluminum removal step of neutralizing the second separated solution to a pH range of from 4.0 to 6.0, then performing solid-liquid separation and removing aluminum in the second separated solution to obtain a third separated solution.
2. The method for processing the lithium ion battery scrap according to claim 1 ,
wherein the lithium ion battery scrap contains copper; and
wherein the leaching step comprises leaving copper contained in the lithium ion battery scrap as a solid and removing the copper by the solid-liquid separation.
3. The method for processing the lithium ion battery scrap according to claim 1 , wherein the oxidizing agent added to the first separated solution in the iron removal step comprises one or more selected from the group consisting of manganese dioxide, positive electrode active materials, and manganese-containing leached residues obtained by leaching the positive electrode active materials.
4. The method for processing the lithium ion battery scrap according to claim 1 ,
wherein the first separated solution contains lithium dissolved in the first separated solution; and
wherein the first separated solution has a molar ratio of lithium to aluminum in the first separated solution (Li/Al ratio) of 1.1 or more.
5. The method for processing the lithium ion battery scrap according to claim 1 , wherein in the aluminum removal step, the second separated solution has a temperature of from 60° C. to 90° C.
6. The method for processing the lithium ion battery scrap according to claim 1 ,
wherein the third separated solution contains dissolved manganese, copper, iron and/or aluminum,
wherein the method further comprises an extraction step of subjecting the third separated solution to solvent extraction to remove manganese, copper, iron and/or aluminum from the third separated solution.
7. The method for processing the lithium ion battery scrap according to claim 6 , wherein the extraction step comprises subjecting the third separated solution to solvent extraction using a mixed extracting agent containing a phosphate ester-based extracting agent and an oxime-based extracting agent.
8. The method for processing the lithium ion battery scrap according to claim 6 , further comprising a cobalt/nickel recovery step of recovering cobalt and/or nickel from an extraction residual solution after the extraction step.
9. The method for processing the lithium ion battery scrap according to claim 8 , further comprising a lithium recovery step of recovering lithium after the cobalt/nickel recovery step.