Recovery of Iron from the Cyanide Tailings with a Combined Process of High Intensity Magnetic Preconcentration-direct Reduction Roasting-magnetic Separation

A combined process of high intensity magnetic preconcentration-direct reduction roast-magnetic separation was applied to recover iron from the cyanide tailings with TFe grade of 30.71%.The tailings were taken from a gold smelting factory in Henan Province.The rough iron concentrate with TFe grade of 44.96% and recovery of 78.27% was obtained after being treated with high intensity magnetic preconcentration at the magnetic field intensity of 1 513 kA/m.The rough iron concentrate was dealt by direct reduction roasting at 1 200 ℃ for 90 min with the mass ratio of rough concentrate,bituminous coal and calcium oxide in 1∶0.2∶0.2.Then the calcined materials were further treated by two-stage grinding and two-stage low intensity magnetic separation.Finally,the reduced iron powder with TFe grade of 92.43% and recovery of 93.2% was obtained.The yield of iron to the cyanide tailings reached 24.24%.The combined process provided a novel approach for recovering refractory iron from the cyanide tailings.