For effective burden distribution in a blast furnace, correct prediction of material trajectory is very important. A mathematical model based on single particle approach has been developed to estimate the material trajectory in a blast furnace fitted with a compact bell-less top. The model has been validated with in-furnace measurements of Tata Steel's 'F' blast furnace. Results obtained regarding the applicability of the model are promising.

Reducibility of iron bearing material is an important property which represents its suitability of reduction in iron making furnaces. It has direct influence on improving productivity and lowering energy consumption in iron making process. The reducibility of iron ore pellets of a specific chemistry can be improved by the optimization of physical parameters such as induration temperature, improving size distribution of fines, improving apparent porosity etc. In this study, the reference pellet is prepared in a typical plant condition and the properties of the reference pellet are considered as base value to improve reducibility index (RI) maintaining other properties at the acceptable limit without altering pellet chemistry. Optimization of induration temperature at the 1250-1275 ºC shows around 74 % RI, which is 5 points more than the base value of 69.5 %. Furthermore, on optimizing additives size, such as limestone fines and anthracite coal fines at-350 mesh and induration temperature of 1250-1275 ºC, RI is improved to 77 %, i.e., 8 points improvement is achieved with respect to the base value.

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Three types of ore fines such as hard ore (HO), blue dust (BD) and friable ore (FO), normally available from a mine show different physical and physicochemical properties. Each of the properties of any individual ore among three may not be suitable to use independently in pelletisation. However, uses of all these three are mandatory. Ores of some poor properties may show other properties excellent. Therefore, any specific poor property of any individual ore can be modified by adding (mixing) other ore which shows that particular property excellent. In order to utilise those three ore fines in pelletisation, mixing of above three ores have been done to get good pellet properties. In industry, the fluctuation in mixing ratio often creates problem in maintaining pellet quality and consistency in spite of maintaining identical basicity and MgO content. Therefore, the required mixing ratio and pellet chemistry has also been optimised in this study. BD, FO and HO has been found to be suitable in the mixing ratio of 70:25:5 with 1.4% MgO. However, with increase in FO beyond 50%, reduction degradation index (RDI) becomes very high (25%). RDI has been decreased to very low level by increasing MgO content from 1.4 to 2% which enables to use FO up to 70% for good quality pellet preparation.

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