Characterization and processing of plant tailings for the recovery of fine garnet - a case study

ABSTRACT

Processing of tailings from a garnet operation was investigated to recover lost garnet. Analyses showed the tailings contained ~15% recoverable garnet. Because current processing utilizes spiral concentrators, different gravity separations were investigated but also included magnetic separation either in the absence or presence of comminution. Combinations of Crossflow separation, tabling and magnetic separation failed with no additional comminution. However, after the tailings were sized and the +1.18 mm fraction was crushed and mixed with the −1.18 mm fraction, a garnet concentrate was obtained at ~15% mass yield with ~80% purity. Results suggest this process will improve economic performance and reduce tailings volume.

KEYWORDS:

• Plant tailings
• garnet recovery
• liberation analysis
• gravity concentration
• magnetic separation

Highlights

• Plant tailings sample was quite fine with 80% material finer than 1.1 mm.

• Garnet content of the sample was 15% by weight and mostly in almandine form.

• A simple flowsheet was developed to recover garnet with partial grinding.

• The recovery scheme reduces tailing volume and addresses tailings disposal issue.

Acknowledgements

The financial assistance from GMA Garnet to conduct the research and permission to publish the paper is greatly appreciated.

Additional information

Funding

This work was supported by the GMA Mining USA [Private Award].