By Minopex – Business Improvement and Technical Department

In mining, the process of flotation is used to separate concentrates from their ores. It is a general mineral processing technique used for almost all metals, as well as some non-metals such as coal and phosphates. Essentially, the flotation process concentrates the value mineral to the point where the smelter will accept it, effectively reducing the overall mass to be processed.

Mass Pulls and the Need for Greater Efficiency

“As we look forward to the future of mining, research within the flotation field is essential to increase efficiencies and find better ways to achieve greater results within the same processes,” says Petrus Jordaan, Metallurgist at Minopex, a DRA Global Company. Finding flotation reagents with greater selectivity could be a key value driver in the search for greater efficiency.

Research Driving a Modern Approach

For this reason, Jordaan embarked on a research journey to determine how better results could be achieved. The research focused on the platinum sector and was carried out at one of the Minopex operated and maintained Concentrators.

The research confirmed that, sound flotation operating principles have led to a higher-than-average platinum recovery rate of around 80 to 83% (above the usual 75 to 80%). “However, that still means you’re effectively throwing away a good fifth of your valuable material,” says Jordaan.

He confirms that it’s a calculation of economics with the smelters. “Although it is working, seeking continuous improvement and greater efficiency is crucial to driving ongoing operational improvements. With the research we conducted, the goal was to improve the recovery, offering mines a huge advantage.”

A Targeted Approach

While most interventions focus on overall recovery improvement, Jordaan’s research went further considering the individual elements in the platinum group metal baskets (platinum, gold, palladium, rhodium, ethidium), to determine the effect of adjustments on each individual element.

“As we began testing multiple different mixtures of dithiophosphates and dithiocarbonates, the goal was to determine whether we could target the more expensive elements to try and improve their recovery specifically,” states Jordaan. “With this targeted approach, we are developing reagents with a higher selectivity that drive greater value.”

The Research Results: Blends for Success

Throughout the research, various lessons were learnt, and several hypotheses proven and disproven. With this information at hand, Jordaan and team were able to identify which reagents were most effective in improving the recovery of the more expensive metals.

The Future for Flotation at Minopex

The team will continue to test and refine reagent blends to ensure the best possible recovery, with the most economic processes. The team is also actively pursuing the development of effective reagents to re-treat previous waste from the mine, ensuring any valuable material left in the waste can also be recovered.

Minopex Business Improvement and Technical Department: Rashnee Chetty, Petrus Jordaan, Naom Maifadi ,Ahmed Ridaa Kader ,Leanie Naude ,Yahnique Petersen