Agglomeration of Hematite Concentrate by Starches

Starches of varying solubilities were investigated as a partial and full bentonite replacements. They were found to be suitable for the pelletization of iron ore concentrate. When utilizing starches of varying solubility as a direct bentonite replacement, dry compression strengths increased by nearly 300 N, as compared to bentonite alone, with the highest solubility starch. This implies that on an equivalent mass basis, starch is a far superior binder than bentonite prior to 500 degrees C. Above this temperature bentonite became the dominating binding factor as starch had combusted and the strengths due to starch were los(t. As a partial bentonite replacement, starch again shows increasing compression strength. The highest strengths were observed where the highest solubility starches were used. Further study has indicated that starch is comprised of insoluble starch granules and soluble starch chains, the latter being the only viable binding agent.