Studies on the relationship between plate water absorption and unfired iron ore pellet strength

Bentonites vary in their ability to absorb water. The plate water absorbance (PWA) test measures the amount of water that a bentonite can absorb. Plant operators disagree on whether or not the PWA value is a good predictor of how a bentonite will perform as a binder. In this study, experiments were conducted to determine the relationship between the bentonite PWA value and the dry compressive strengths of iron ore pellets. Pellet strength correlated poorly with the standard PWA test results, where bentonites are allowed to absorb distilled water for 18 hours. Correlations improved, but remained marginal, when PWA was measured in water having high concentrations of cations, representative of the water that remains in the iron ore during pelletization