Production Test of High-carbon Ferromanganese Using a Shaft Furnace with Coke Packed Bed Injected with Highly Oxygen Enriched Air and a Large Quantity of Pulverized Coal.

Abstract

High-carbon ferromanganese has been produced by electric arc furnace in Japan. But its production cost has increased because of a speedy rising of electricity cost and Japanese ferromanganese has lost competitiveness in the international market. So, for the purpose of decreasing its production cost, high-carbon ferromanganese production tests (production rate=1.9-4.3 t/d) were performed using a melting test furnace with coke packed bed injected with highly oxygen enriched air and a large quantity of pulverized coal. Moreover the operation indices of a commercial plant of 170 t/d in production capacity were estimated by heat and mass balance model, and following results were obtained.(1) In this test, high-carbon ferromanganese of [Mn]=75% was produced stably using the coke blended with 56% non-coking coal, with coal rate of 1 502 kg/t, coke rate of 1 087 kg/t and productivity of 3.11 t/(d·m3).(2) The total coal consumption of the commercial plant of this method is estimated to be less than that of the blast furnace in spite of higher fuel rate because a large quantity of pulverized coal is used in this process. Through these investigations, this process seems to have a prospect of being available as a ferromanganese production process instead of electric furnace method.