Method to improve preheated and fired strengths of haematite pellets using boron compounds with organic binders

Organic binders as alternatives to bentonite in iron ore pelletisation have found limited application since they fail to give enough mechanical strength to preheated and fired pellets. This paper describes the use of alternative binders to bentonite for haematite ore pelletisation. Organic binders (carboxyl methyl cellulose, corn starch, dextrin) and agglomeration aid chemicals (polymer and flocculants) and boron compounds (colemanite and borax pentahydrate) were tested as binder alone or in combination. The influence of the boron compound added organic binders on the preheated and fired pellet strengths was determined. The results showed that the compressive strengths of preheated pellets at 1000 degrees C made with organic binders can be improved with the addition of colemanite. The compressive strengths of fired pellets at 1300 degrees C produced with organic binders plus colemanite were found to be significantly greater than those of pellets bonded with the reference bentonite binder.