Technology for an increased portion of fine ore in the COREX® process

COREX is a smelting reduction process based on lumpy ore and coal. The fine-ore portion in the ore burden charged into the reduction shaft is limited to about 5% to secure uniform gas penetration and stable operation of the reduction shaft. Fine-ore injection into the COREX process, as it has been developed jointly by VAI (VOEST-ALPINE Industrieanlagenbau GmbH, Austria), RIST (Research Institute of Industrial Science and Technology, Korea) and POSCO (Pohang Iron and Steel Company Ltd., Korea) since 1992, offers the potential to use up to 25% of fine-ore and iron-containing fines in the COREX process, which leads to an increased flexibility, to an enlarged capacity, and to improved economics of the COREX process. Additionally, it allows the use of ore fines from material handling and the direct use of iron-bearing fines of the metallurgical plant. Lab scale, cold and hot bench scale tests were used to assess the physical and the metallurgical behaviour of ore fines under process conditions. An industrial-scale pilot plant designed according to the findings of these tests was attached to the COREX C-2000 plant of POSCO. The results of test campaigns on this plant are discussed and the economic benefits for the COREX process are depicted.