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The Corex process has been developed as an alternative to the blast furnace where 80-85% noncoking coal and 15-20% coke is used as fuel for heat generation, production of reduction gases and to maintain adequate char bed permeability in the melter-gasifier. Non-coking coals, which can be used in Corex, have to meet certain physical, chemical and high temperature properties for stable process and to attain high performance levels. JSW Steel operates largest Corex based integrated steel plant with two modules each of 0 . 8 Mtpa capacity where several coals have been used so far and the type of coal used significantly influenced operation. Statistical analysis shows that the significant parameters affecting fuel rate are moisture, volatile matter, slag rate and melting rate. It was observed that at high rate of production, stability and permeability of char bed becomes critical hence coals producing char of high strength after reaction are required.

is an integrated steel plant of 3 . 8 mtpa capacity, with two Corex and two blast furnace (BF) units for producing hot metal. It has started its integrated steel plant operation with Corex ironmaking technology and then synergised with the conventional BF ironmaking during plant expansion. Both these ironmaking furnaces are unique in nature, and have different operation philosophies. The performances of these units depend on the raw material charged, operational philosophies, maintenance, etc., and have their own advantages and disadvantages. This paper brings out the comparison between these ironmaking processes through the usage of raw material inputs, plant operation, maintenance, quality of hot metal and byproducts. This paper also highlights the benefits due to synergistic combination of Corex and BF in an integrated steel plant.

A composite model for computational analysis of the Corex process of ironmaking has been developed. The model combines a set of common material and heat balance equations. Taking user specified inputs, the model is capable of determining the consumption of raw materials and fluxes, the volume and composition of the slag and the volume and composition of reducing gases from the melter-gasifier. The accuracy of the prediction of Corex operational parameters is competitive, and the model enables computation of changes in process pathways induced by a modification of Corex raw materials, slag composition, hot metal chemistry and other parameters. The model allows optimisation of the operational parameters of the Corex process.

The scarcity of good quality coking coal for the blast furnace (BF) has made steel makers look for an alternative iron-making process that requires little or no coke. The Corex process has been developed as an alternative to BF iron-making, which uses non-coking coal and a small amount of coke as fuel, and pellet/lump ore as iron-bearing feed. JSW Steel operates two Corex units each of 0?8 Mtpa, commissioned in 1998 and 2001 respectively. Iron oxides and non-coking coals have to meet certain physical, chemical and high temperature properties for stable operation and to attain high performance levels. Experience of the Corex operation with various coals and iron oxides over the years has helped in understanding the influence and sensitivity of raw materials on its performance and develop new raw material specifications. Statistical analysis of plant data showed that the significant parameters affecting fuel rate and production are moisture, volatile matter, char strength after reaction of coal, reduction disintegration index (RDI; %, -6?3 mm) of pellets and slag rate. This helped achieve the most efficient operating parameters, surpass rated capacity and utilise steel plant waste. The present paper brings out the impact of various raw material properties, and the modified specifications of coal and iron oxides for Corex.