Innovative Development on Agglomeration of Iron Ore Fines and Iron Oxide Wastes

In steel industry and in mines, a significant amount of ultra-fines waste iron oxides and iron ore fines is generated. Utilizations of these fines are required to reduce the environmental hazards and conserve the natural resources. Some of these fines are normally used in sintering practice. However, sintering has a limitation of accepting ultra-fines materials. Pelletizing can use ultra-fine iron oxides. However, suitable technology is required for preparation of good quality pellets. Some of the fines, viz. blast furnace (BF) flue dust, Linz Donawitz (LD) converter sludge etc., are not suitable due to their high alkali and Zn content. Some other material like slime is not considered to be suitable in normal pelletizing practice, because of its high alumina and silica content and excessively fine size. On the other hand mill scale and blue dust have poor green bonding property. Therefore, suitable technologies are required to be developed for their utilization/recycling. This paper discusses the various technologies developed such as (i) developing flux for basic oxygen steelmaking process, (ii) improved pelletizing practice for better reducibility, lower reduction degradation and replacing bentonite binder, and (iii) special quality sinters for improving micro-fines utilization. These technologies may have very good application potential.