Hard disk of computers is the most essential part, which plays significant role for
programming the computers. Hard disk contains permanent Nd-Fe-B magnet as a most powerful
magnet, these magnets become waste rapidly by reaching its end-of-life, therefore the metallic content
(Nd, Pr, Dy) in it is also act losses which is present in limited stock in nature therefore recycling of
these waste is necessary to get the metallic content from it and also preserve the natural resources. This
study provide a proper technique and development of hydrometallurgical process to extract REMs
from Nd Fe B magnets, which includes general flow chart such as manual dismantling,
demagnetization (300 °C, 3h), crushing to get the material in its homogenous form, leaching (2M
H SO , 100 g/L, 25 °C, 1h), solvent extraction of REMs (pH~2, 15 min), air sparging to remove iron
from the solution (pH~3.5, 50-60 °C, 1h), etc. about >95% of rare earth metals were recovered by this
techniques and remaining metals left in the liquor can be recovered by further hydrometallurgical
processes
