Method for regenerating lithium precursor and system for regenerating lithium precursor
In a method for regenerating a lithium precursor, an electrode active material mixture collected from a lithium secondary battery is prepared. The electrode active material mixture is reduced in a dry rotary heating reactor to form a preliminary precursor mixture. A lithium precursor is selectively recovered from the preliminary precursor mixture. Recovery yield and selectivity can be improved using the dry rotary heating reactor.
1 . A method for regenerating a lithium precursor, the method comprising:
preparing an electrode active material mixture collected from a lithium secondary battery;
forming a preliminary precursor mixture by reducing the electrode active material mixture in an indirect firing rotary kiln; and
selectively recovering a lithium precursor from the preliminary precursor mixture,
wherein the forming of the preliminary precursor mixture comprises contacting the electrode active material mixture with a reductive reaction gas which is supplied from both a rear end and a front end longitudinal direction of the indirect firing rotary kiln,
the reductive reaction gas supplied from the rear end in a longitudinal direction of the indirect firing rotary kiln forms a counter flow with respect to the electrode active material mixture supplied to the front end in the longitudinal direction of the indirect firing rotary kiln, and
the reductive reaction gas supplied from the front end in the longitudinal direction of the indirect firing rotary kiln forms a co-flow with respect to the electrode active material mixture supplied to the front end in the longitudinal direction of the indirect firing rotary kiln,
wherein the forming of the preliminary precursor mixture comprises rotating the indirect firing rotary kiln at a rate from 5 to 200 rpm along an axis in a longitudinal direction while moving the electrode active material mixture in the longitudinal direction of the indirect firing rotary kiln.
2 . The method of claim 1 , wherein the reductive reaction gas is introduced together with the electrode active material mixture to the front end in the longitudinal direction of the indirect firing rotary kiln.
3 . The method of claim 1 , wherein the preliminary precursor mixture comprises preliminary lithium precursor particles and transition metal-containing particles.
4 . The method of claim 3 , wherein the preliminary lithium precursor particles include lithium hydroxide, lithium oxide and lithium carbonate.
5 . The method of claim 3 , further comprising recovering a transition metal precursor by treating the transition metal-containing particles with an acid solution.
6 . The method of claim 1 , wherein the selectively recovering of the lithium precursor comprises hydrating the preliminary lithium precursor particles to generate the lithium precursor and recovering the generated lithium precursor.
7 . The method of claim 6 , wherein the hydrating of the preliminary lithium precursor particles comprises collecting the lithium precursor before the transition metal-containing particles.
8 . A method for regenerating a lithium precursor, the method comprising:
preparing an electrode active material mixture collected from a lithium secondary battery;
forming a preliminary precursor mixture by reducing the electrode active material mixture in an indirect firing rotary kiln; and
selectively recovering a lithium precursor from the preliminary precursor mixture,
wherein the forming of the preliminary precursor mixture comprises contacting the electrode active material mixture with a reductive reaction gas which is supplied from both a rear end and a front end longitudinal direction of the indirect firing rotary kiln,
the reductive reaction gas supplied from the rear end in a longitudinal direction of the indirect firing rotary kiln forms a counter flow with respect to the electrode active material mixture supplied to the front end in the longitudinal direction of the indirect firing rotary kiln, and
the reductive reaction gas supplied from the front end in the longitudinal direction of the indirect firing rotary kiln forms a co-flow with respect to the electrode active material mixture supplied to the front end in the longitudinal direction of the indirect firing rotary kiln,
wherein the forming of the preliminary precursor mixture is performed at a reaction temperature from 250 to 600° C.