Multi-stage calcining method for neodymium iron boron waste

The invention discloses a neodymium-iron-boron waste multi-stage calcination method which specifically comprises the following steps: (1) a high-temperature calcination stage: putting neodymium-iron-boron waste into a calcination furnace, introducing air, performing high-temperature calcination on the neodymium-iron-boron waste, and detecting the oxygen content of flue gas generated by calcination; (2) secondary high-temperature calcination stage: performing secondary high-temperature calcination on the product calcined in the step (1); (3) recovering the flue gas generated in the step (1), and introducing the flue gas into the high-temperature calcination stage in the step (1) and/or the secondary high-temperature calcination stage in the step (2) to adjust the reaction temperature; and (4) cooling. According to the neodymium-iron-boron waste multi-stage calcination method, flue gas generated after heat recovery is introduced into the high-temperature calcination stage and/or the secondary high-temperature c