Characterization of Pellets made of Iron Fines from Noamundi Mines

Abstract

Pelleitization process was originally developed in United States of America to form spherical balls of ultra fine minerals. Now-a-days, in almost all countries this method is being in use for the utilization of fines of iron ore as a charge material to blast furnace iron making and also for DRI production. During mining and beneficia-tion of iron ore a considerable amount of fines around 40 to 50% is produced. Fines are produced as flotation con-centrate during selective beneficiation and blast furnace operation as by product. These fines cannot be charged directly into the blast furnace because they block ascen-ding gases and affect the smooth functioning of furnace. For utilization of these fines the process of pellet-ization has been developed. Very fine particles cannot be used in sinter making because they create very low permea-bility of the bed thereby increasing the fuel consumption and lowering specific output. These fines can be agglom-erated into a comparatively large size pellets having 6 to 20mm diameter by mixing them with binders and fluxes in presence of moisture. The green pellets are then heat-hardened at a temperature around 1300oC to improve its strength for handling, transportation and storage. Due to development of mini blast furnace, electric arc furnace and for production of sponge iron, these iron ore pellets are frequently used that increases the demand for the production. Indian iron ore fines are getting transported due to shortage of resources for utilising them, however, more number of pelletizing plants going to be installed. Demand for pre-reduced pellets for the manufacture of different varieties of steels is increasing day by day and new solid reductants based sponge iron plants are being commissioned. In the existing blast furnace an increase in production by at least 25 to 35% can be achieved by using pre reduced iron ore. Pre-reduced iron ore pellets have been established as a good substitute for steel scrap in an electric arc furnace which enhances the productivity of the arc furnace. Iron and steel industry needs reliable characterisation and assessment data on raw materials. Therefore, it is worthwhile to find out correct techniques for assessment of quality of raw materials and relate this to blast furnace performance. The quality of raw materials affects the quality of the final product to a great extent and the cost of operation as well. In the present project work, an attempt has been made to study “the charac-teristics of pellets made of iron ore fines from Noamundi mines.”