Various rare earth particles magnetic separation using magnetic fluid and paramagnetic liquid

•Water based ferrofluid and paramagnetic liquid can produce various magnetic susceptibility of liquid.•The different magnetic susceptibility of rare earth particle mixture can be separated by magnetic separation to control the liquid magnetic susceptibility.•The most rare earth mixtures of two neighboring atomic numbers have higher separation factors in magnetic separation, such as Ce-La, Pr-Ce, Eu-Sm, Gd-Eu, Dy-Tb, Tm-Er, and Lu-Yb mixture.•The separated particles are easily washed by water, recovered, and the diluted ferrofluid can be recycled.