The invention relates to a low-grade
iron ore direct reduction method, which comprises: calculating and taking a certain amount of
coal powder, an additive, a binder and water by adopting the
dry basis mass of
iron ore to be treated as reference; uniformly mixing the taken components, and completely
wetting to obtain an internal matching
coal; uniformly mixing the internal matching
coal and
iron ore particles to be treated, and granulating to obtain granulated
pellets; directly conveying the obtained granulated
pellets into a
rotary kiln, carrying out
drying, pre-heating, and reduction
roasting to carry out coal base direct reduction so as to obtain a reduced material, cooling the reduced material in the absence of air, and carrying out dry
magnetic separation to obtain the reduced
roasting pellets and the
residual carbon; and carrying out treatments such as ore
grinding and
magnetic separation on the reduced
roasting pellets to obtain iron concentrate, or carrying out re-
grinding and re-
magnetic separation to obtain the reduced
iron powder, wherein the obtained
residual carbon can be recycled. With the method of the present invention, the low-grade iron ore can be effectively treated, the internal matching coal and the additive are used to granulate, the wet pellets enter the
kiln, the coal base direct reduction is performed, the magnetic separation is performed to obtain the high-grade iron concentrate or the directly-reduced
iron powder, and the method has characteristics of energy saving, high efficiency, and rapidness.