Roasting reduction-magnetic separation of oolitic-hematite and preparation of cementitious materials

Aimed at utilizing oolitic hematite comprehensively and reducing discharge of solid wastes, a series of experiments to extract iron by coal-based roasting reduction-magnetic separation technology and prepare cementitious materials by using magnetic separation tailings were carried out. The experiment results show that when the amount of reductant is 30wt%, the roasting temperature is 1200°, the reduction time is 60min and the magnetic field intensity is 111kA·m^-1, the iron grade of the concentrate and iron recovery rate can reach 90.78% and 92.53%, respectively. Meanwhile, the cementitious materials made of the magnetic-separation tailings, blast furnace slag and other property modifiers can meet the requirements of 42.5R cement in such respects as compressive strength, setting time and soundness.