Method for recovering lithium from waste lithium iron phosphate material

• Main Authors: TAN FENG, RUAN DINGSHAN, ZHENG XIANLIANG, CHEN RUOKUI, SUN JIE, QIAO YANCHAO, LI CHANGDONG
• Format: Patent
• Language: Chinese; English
• Published: 05.11.2021
• Subjects: CHEMISTRY; COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM,RUBIDIUM, CAESIUM, OR FRANCIUM; INORGANIC CHEMISTRY; METALLURGY

The invention discloses a method for recovering lithium from a waste lithium iron phosphate material, which comprises the following steps of: S1, adding water into a waste lithium iron phosphate material to prepare slurry, controlling the pH value of the slurry to be 0.5-2.0, controlling the oxidation-reduction potential of the slurry to be 0.05-1.2 V, filtering and taking filter residues to obtain a material A; S2, adding sulfuric acid into the material A, and heating in the atmosphere of air or oxygen at 100-400 DEG C to obtain a material B; S3, adding water into the material B, stirring, filtering and taking filtrate to obtain a material C; S4, controlling the pH value of the material C to be 9-11, filtering and taking filtrate to obtain a material D; S5, enabling the material D to pass through ion exchange resin to obtain a material E; and S6, adding the material E into a sodium carbonate solution, and taking a solid after reaction to obtain lithium carbonate. According to the method disclosed by the inve