The present disclosure belongs to the technical field of battery recycling, and discloses a recycling method and use of lithium iron phosphate (LFP) waste. The method includes the following steps: mixing the LFP waste with water to prepare a slurry; adjusting a pH of the slurry to higher than 7.0 with an alkali, and heating to react; filtering a resulting mixture to obtain a filter residue; dissolving the filter residue in an acid, and filtering to obtain a filtrate; adding an oxalate-containing solution to react, and aging and filtering a resulting mixture to obtain a filter cake and a precipitation mother liquor; and subjecting the filter cake to slurrying, washing, and free water removal to obtain ferrous oxalate.

The present disclosure belongs to the technical field of battery recycling, and discloses a recycling method and use of lithium iron phosphate (LFP) waste. The method includes the following steps: mixing the LFP waste with water to prepare a slurry; adjusting a pH of the slurry to higher than 7.0 with an alkali, and heating to react; filtering a resulting mixture to obtain a filter residue; dissolving the filter residue in an acid, and filtering to obtain a filtrate; adding an oxalate-containing solution to react, and aging and filtering a resulting mixture to obtain a filter cake and a precipitation mother liquor; and subjecting the filter cake to slurrying, washing, and free water removal to obtain ferrous oxalate.

The present disclosure provides a method for purifying nanostructured material comprising carbon nanotubes, metal impurities and amorphous carbon impurities. The method generally includes oxidizing the unpurified nanostructured material to remove the amorphous carbon and thereby exposing the metal impurities and subsequently contacting the nanostructured material with carbon monoxide to volatilize the metal impurities and thereby substantially remove them from the nanostructured material.

Methods and reactor systems are provided for extracting metals, such as nickel, cobalt, and iron, from reduced, activated metal compounds (feed materials). Feed materials may be derived from mixed hydroxide precipitate. Feed materials and carbon monoxide gas are delivered into an extraction reactor of a reactor system, such as a shell tube heat exchanger. A flow path therein directs the feed material downward and the carbon monoxide gas upward, enabling contact therebetween, forming at least one metal carbonyl gas and a solid residue therein. The flow path further directs the upward flow of metal carbonyl gases, and the downward flow of the residue. Methods and reactor systems may further purge the residue: using nitric oxide to convert any remaining dicobalt octacarbonyl therein to cobalt tricarbonyl nitrosyl gas; using an inert gas to removing any cobalt tricarbonyl nitrosyl therein; and using an inert gas-oxygen mixture, to form a passivated residue.

Methods and reactor systems are provided for extracting metals, such as nickel, cobalt, and iron, from reduced, activated metal compounds (feed materials). Feed materials may be derived from mixed hydroxide precipitate. Feed materials and carbon monoxide gas are delivered into an extraction reactor of a reactor system, such as a shell tube heat exchanger. A flow path therein directs the feed material downward and the carbon monoxide gas upward, enabling contact therebetween, forming at least one metal carbonyl gas and a solid residue therein. The flow path further directs the upward flow of metal carbonyl gases, and the downward flow of the residue. Methods and reactor systems may further purge the residue: using nitric oxide to convert any remaining dicobalt octacarbonyl therein to cobalt tricarbonyl nitrosyl gas; using an inert gas to removing any cobalt tricarbonyl nitrosyl therein; and using an inert gas-oxygen mixture, to form a passivated residue.