METHOD AND EXTRACTION DEVICE FOR EXTRACTING AND PREPARING BATTERY-GRADE LITHIUM CARBONATE FROM P507 RAFFINATE

Disclosed are a method and device for extracting and preparing battery-grade lithium carbonate from a P507 raffinate. The method comprises steps of impurity adjustment, extraction, purification, reverse extraction, alkalization, crystallization, separation, drying, the impurity adjustment comprises: adjusting a pH value of the P507 raffinate to be 8.5 to 10.5 with lithium hydroxide or alkali, and filtering to obtain a filtrate for later use; the alkalization comprises: heating a lithium solution to 85° C. to 95° C., adding lithium hydroxide or alkali to adjust a pH value to be 9.0 to 13.0, maintaining a temperature at 85° C. to 95° C. and standing for 2 hours to 8 hours, and then filtering to obtain a filtrate for later use; and the crystallization comprises: introducing compressed air into the filtrate after alkalization, evaporating and concentrating at the same time, and discharging and cooling when fine crystals exist in the concentrated solution.