Method for extracting iron by carrying out suspension magnetizing roasting and cyanide breaking-magnetic separation on high-iron cyanidation tailings

The invention provides a method for extracting iron by carrying out suspension magnetizing roasting and cyanide breaking-magnetic separation on high-iron cyanidation tailings. The method comprises thefollowing steps of: (1) crushing and grinding the high-iron cyanidation tailings; (2) introducing the high-iron cyanidation tailings into a pre-oxidation suspension roasting furnace, enabling high-temperature flue gas to enter the pre-oxidation suspension roasting furnace, heating the tailings powder to 650-750 DEG C in a suspension state for cyanide breaking roasting, and removing the residual solid material oxidized slag powder; (3) introducing the oxidized slag powder into a reduction roasting furnace, introducing coal gas and nitrogen into the bottom of the reduction roasting furnace, carrying out reduction roasting on the oxidized slag powder at 500-600 DEG C in a suspension state, and removing the residual reduced slag powder; (4) cooling the reduced slag powder, and then carrying out first-stage ore grindi