43results about How to "Raise the average valence" patented technology

This invention provides a method for recycling lithium manganese iron phosphate waste. The recycling method includes the following steps: (1) mixing lithium manganese iron phosphate waste with a first acid solution, introducing sulfur dioxide and oxygen, and performing oxidative leaching to obtain a leaching slurry; (2) subjecting the leaching slurry to copper removal treatment to obtain leaching residue and leaching solution; (3) mixing the leaching residue from step (2) with a second acid solution, adjusting the pH value to perform a first precipitation reaction to obtain manganese iron phosphate; and subjecting the leaching solution from step (2) to lithium extraction treatment to obtain purified lithium salt. The recycling method provided by this invention has a better oxidation effect, does not introduce a large amount of cationic impurities, can realize the full-component recovery of lithium manganese iron phosphate battery cathode materials, and can obtain battery-grade purified lithium salt materials and the precursor manganese iron phosphate products required for battery-grade lithium manganese iron phosphate cathode materials; and the process cost is low, which improves the added value of the products and better meets the actual production needs.