This study explores the innovative recycling of neodymium (Nd) permanent magnet scrap to synthesize Fe 3 O 4 , a high‐capacity anode material for secondary batteries, by leveraging the Fe oxalate solution produced during recycling. The traditional process of recovering Fe from permanent magnets in the form of oxides produces products with limited economic viability and usability. For the first time, we have successfully synthesized Fe 3 O 4 as an anode material for lithium‐ion (Li‐ion) secondary batteries from scrap Nd magnets. We address the existing challenge by employing a novel approach: hydrothermal synthesis of crystalline FeC 2 O 4 ·2H 2 O from the Fe leachate, extracted via oxalic acid leaching from a mixed phase of NdF 3 ‐Fe 2 O 3 controlled during fluorination heat treatment while recycling. The recovered FeC 2 O 4 ·2H 2 O is subsequently phase‐transferred to Fe 3 O 4 under an Ar atmosphere. To overcome the inherent low conductivity and rate capability of Fe 3 O 4 , a carbon‐coating process utilizing dopamine HCl is implemented. The developed C‐Fe 3 O 4 anode material exhibits a significant capacity retention of 428 mAh/g after 500 cycles at 1C, showcasing its potential for use in high‐performance secondary batteries and contributing to the sustainable recycling of critical materials.