METHOD FOR REMOVING FLUORINE IN POSITIVE ELECTRODE LEACHATE OF LITHIUM BATTERIES

• Main Authors: OUYANG, Shibao, CHEN, Ruokui, RUAN, Dingshan, QIAO, Yanchao, LI, Changdong, CAI, Yong
• Format: Patent
• Language: Chinese; English; French
• Published: 04.05.2023
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMISTRY; COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM,CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THERARE-EARTH METALS; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; INORGANIC CHEMISTRY; METALLURGY; PRETREATMENT OF RAW MATERIALS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

Disclosed is a method for removing fluorine in a positive electrode leachate of lithium batteries, comprising: adding acid and an oxidizing agent to battery powder for leaching, and removing impurities from the obtained leachate to obtain a fluorine-containing solution; adding dawsonite to the fluorine-containing solution, and meanwhile adding sulfuric acid, stirring for reaction at a certain temperature, and performing solid-liquid separation to obtain fluorine-removed solution and filter residues; and washing the filter residues to obtain crude sodium hexafluoroaluminate. According to the present invention, the dawsonite is used for removing fluorine from waste lithium batteries, the dawsonite has good selectivity, does not react with nickel, cobalt, manganese, lithium and the like in the solution, and only reacts with fluorine ions in the solution, so that the purpose of selectively removing fluorine is achieved, and the loss of nickel, cobalt, manganese and lithium metals in the solution is avoided. Accor