Abstract: Ruyang Molybdenum Mine originally adopted a simple flowsheet of direct low intensity magnetic separation to recover the magnetite from the tailings of molybdenum flotation. However, the iron concentrate had an iron grade of only about 20% due to a very fine dissemination particle size of the magnetite. Therefore, the mine finally adopts a two-staged grinding-separation process after two technical transformations. And a secondary classification featuring a tube mill in direct connection with hydrocyclones in the secondary stage grinding, enabling the final grind fineness to be over 95% -400 mesh, the iron ore to have a grade of higher than 63% and the recovery to increase by more than one percentage point compared to that before the second technical transformation. This has brought remarkable economic benefits to the mine.

Key words: Tailings of molybdenum flotation, Magnetite, Comprehensive recovery, Staged grinding-separation, Tube mill, Technical transformation