Recovery of rare earth and cobalt from Co-based magnetic scraps

The reuse of RE and cobalt in Co-based magnetic scraps was studied.The optimized feat lixiviated condition was:200 mesh,sulfuric acid dosage was of 1.4 times theoretic dosage,temperature was 80 oC and leaching time 1 h.The optimum technology conditions was:Na2S2O8 dosage was of 8 times theoretic dosage,oxidation temperature 80 oC,oxidation time 2 h and pH=4.5.Rare earth was precipitated by saturated(NH4)2C2O4 solution,after roasting of rare earth oxalate,rare earth oxide was received.Cobalt-iron residue was soaked by hydrochloric acid,the Fe(OH)3 was preferential solution,pH was adjusted to 1.4 by hydrochloric acid,Co(OH)3 did not dissolve,cobalt and iron were separated,after roasting of Co(OH)3,cobalt oxide was received.The total recovery of cobalt was found to be 97% and rare earths was 96%.