On the production of iron ore superconcentrates by high-intensity wet magnetic separation

Abstract

Direct reduction of iron ore to produce electric furnace feed for steelmaking is becoming economically important on a worldwide scale. For this application an iron ore superconcentrate containing less than 2% silica is demanded. Pilot plant and commercial operations have shown that high-intensity wet magnetic separation is well adapted to meet this specification with high recovery and attractive capital and operating costs. Tests with the Jones separator have produced superconcentrates containing less than 1.5% silica with over 90% iron recovery from preconcentrates produced by sizing or by gravity or low-intensity magnetic separation. Estimated total capital and operating costs to produce a ton of superconcentrate by high-intensity wet magnetic separation are $0.43 for retreatment of specular hematite spiral concentrate, $0.47 for Brazilian hematite fines, and $0.49 for magnetite.