LIXIVIAÇÃO ÁCIDA DE BATERIAS ÍON-LÍTIO

• Main Authors: Rafael Gundim Silva, Júlio Carlos Afonso, Claudio Fernando Mahler
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química
• Series: Química Nova
• Subjects: lithium-ion battery; metals recovery; solvent extraction; cobalt; lithium
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422018000500581&lng=en&tlng=en

This paper describes a route for recovering cobalt and lithium from spent Li-ion batteries via acidic leaching. Sulfuric, hydrochloric, hydrofluoric and formic acids were used as leachants. Hydrogen peroxide was added as reductant, except for formic acid since it is itself a reductant. Experiments were run at 25-40 ºC for 1-3 h. Under the best optimal conditions, the leaching efficiency order was HCl ≈ HF > H2SO4 > HCOOH. Over 90 wt.% of cobalt and lithium were leached by the inorganic acids. The insoluble matter corresponds mainly to the carbon from the cathode. Co(II) was extracted with D2EHPA 16 vol.% diluted in n-hexane at pH ~5 (A/O ratio 1/1 vol/vol, one stage, 25 ºC). Co(II) striping was possible using a dilute leachant (1-2 mol L-1 HCl or H2SO4, 4-5 mol L-1 HF or HCOOH). Lithium was isolated from the raffinate by precipitation as carbonate or phosphate.