Practical Advances in Reagent Optimisation for PGM Flotation

Background

The increasing complexity of platinum group metal (PGM) ores and tightening economic constraints require practical, data-driven approaches to reagent optimisation. This webinar presents an integrated evaluation of reagent strategies aimed at improving flotation performance through depressant optimisation, co-collector optimisation, and advanced data analytics.

Laboratory flotation tests investigated the optimisation of a guar gum-based co-depressant and dispersant system to suppress pyroxene and associated gangue minerals. Increasing the co-depressant dosage from 0 to 50 g/t and dispersant from 1600 to 1900 g/t reduced chrome entrainment by 9.6% (Cr 2 O 3 recovery from 11.6% to 10.5%) and improved 4E recovery from 66.6% to 69.8%. Concentrate grade increased by ~8.0% (35.5 g/t to 38.3 g/t) at stable mass pull (8.6–8.8%), with optimal conditions identified at 1700 g/t dispersant and 50 g/t co-depressant.

A second study applied Response Surface Methodology to evaluate co-collectors as partial substitutes for sodium isobutyl xanthate (SIBX) in Great Dyke PGM flotation. Significant synergistic interactions (p < 0.05) were observed, with a strong model fit (R 2 > 0.7). The optimised regime reduced SIBX dosage by 75% while increasing 4E recovery by 3%, with no significant change in concentrate grade.

In parallel, a MetSoP co-collector was evaluated during an industrial plant trial using the Optimaviz analytics platform. Statistical analysis showed a 3% increase in PGM recovery and a 2% increase in concentrate grade, with no increase in reagent consumption. Machine learning tools further enabled development of a predictive model linking co-collector dosage to recovery performance.

These results demonstrate that practical reagent optimisation can significantly improve flotation efficiency in complex PGM ore systems.