Sampling, Characterization, and Evaluation of Midwest Clays for Iron Ore Pellet Bonding

摘要

The potential of using glacial lake clay from Minnesota, as well as other areas, as a binder for iron ore pellets was investigated. The best clay-characterizing procedures for predicting binder effectiveness were the cation exchange capacity using the methylene blue method and the plate water absorption test. The best clay binder was found in the Red River Valley. However, compared to a typical western bentonite at the 0.5-pct-addition level, addition of about 2 pct Minnesota clay was required to obtain comparable unfired (green) pellet strengths. Soda ash addition only slightly improved the binding properties of Minnesota clay, but considerable improvement was obtained by the addition of a small quantity of water-absorbing organic compounds.