Experimental Study of Dry Desliming Iron Ore Tailings by Air Classification

ABSTRACT

Techniques for dry processing low-grade iron ores and tailings are being investigated. Dry desliming tests using a rotating wheel air classifier and factorial design were performed on a difficult-to-treat low-grade high-goethite Australian iron ore tailings. The results were compared with theoretically ideal size separation and a hydrocyclone desliming study using the same tailings. The air classifier performance was poorer than the hydrocyclone due to agglomerated particles in the feed, including fines coating coarser particles. The “fish hook” effect was observed and discussed. After dry desliming, the silica and alumina contents of a selected product were 30% and 26% lower, respectively.

KEYWORDS:

• Air classification
• dry beneficiation
• low-grade iron ore tailings

Acknowledgments

The authors would like to thank CSIRO Mineral Resources and the University of Queensland for their collaboration on this project. A token of appreciation is extended to staff at CSIRO, namely, Sarath Hapugoda, for generating micrographs of samples, and Cory Nedwich, for helping with the dry sizing of test products.

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

This work was supported by CSIRO Mineral Resources.