FLOTATION TECHNOLOGY
is returned to the process.
The most significant P29 pilot plant site testing to date has been BHP’ s Carrapateena copper operation in South Australia, where a pilot plant in October 2025 will reach a year of operation. Holdsworth:“ The first two campaigns of running the plant in November and December 2024 delivered the metallurgical performance that BHP Carrapateena wanted to see, as they had a threshold of copper recovery and we exceeded that, which they were very pleased with. This period saw us carry out multiple tests, so that gave them confidence. They then basically handed the pilot plant operation back to us, which allowed us to do our development work, plus set our operating boundaries etc. And then in June 2025, we were requested to repeat previously achieved recoveries, and we have done that – so we have demonstrated an ability to deliver consistent results.”
In the meantime, CiDRA has done some Class 5 engineering studies together with Worley. For both BHP and for Rio Tinto, with whom CiDRA is also in discussions with, the most important factor is P29’ s potential to bring a significant reduction in comminution energy. It also translates into significant reductions in overall CAPEX and OPEX depending on application.
“ So the future value proposition is exciting for our potential customer base. The pilot plant has demonstrated repeatable metallurgical performance. I think what we are now seeing is that everyone is aligning. The next step is to do a demo scale plant. So we are currently discussing the early phases of that programme. We are working with BHP on that and it will likely be located at an operational site in Australia. We expect the demo plant will be advanced by a consortium including us, Weir, Worley, and industry partners. The basis of it is how do we advance this technology for everyone’ s benefit in the industry. But because it’ s first of a kind technology, we are looking at how do we accelerate it fast but reduce the risk across multiple parties. To move forward, there are questions around what happens at scale. A pilot plant and pipes at 20 mm with 12 mm cubes is different than a 300 mm pipe with thousands of cubes.”
The focus of these miners is future greenfield coarse recovery, lower comminution energy, and lower water usage plus coarse dry stack tails, and safer tailings. Holdsworth:“ But it is also looking at testing new combination methodologies, because now you can recover coarse particles, can you break the particle along the mineral boundary and get better performance? This could even include novel rock breakage technology using roll crushers.”
Holdsworth added that BHP’ s Carrapateena site team in particular have shown a high level of commitment, support and drive – from Rhys Jones and before him Joe Seppelt. They see the mineral processing optimisation upside but also the sustainability benefits, especially in energy and water usage terms.
Evaluation of Woodgrove DFR flotation technology for fine iron ore
The recovery of fine iron particles remains one of the most difficult challenges in mineral flotation. Conventional tank cells often struggle with poor selectivity, high gangue entrainment, and reduced metallurgical performance in the critical fines fraction(< 45 µ m). These limitations not only restrict overall recovery but also result in significant iron losses to tailings.
At the Flotation 2025 conference, Vale and Woodgrove will present results from a joint pilot-scale evaluation of Woodgrove’ s Direct Flotation Reactor( DFR ®), led by Dr. Neymayer Lima of Vale. This collaboration represents one of the most comprehensive assessments of DFR technology in iron ore applications, with particular focus on overcoming the limitations of conventional fines flotation.
The DFR employs a distinctive design that departs from traditional mechanical cells. Its staged flotation mechanism, controlled energy profile, and innovative froth washing system work together to improve bubble-particle attachment while reducing the carryover of unwanted minerals. By eliminating much of the turbulence and back-mixing inherent in conventional units, the DFR creates more efficient conditions for recovering fine iron particles and producing cleaner concentrates.
Pilot plant trials provided a direct comparison between DFR units and conventional mechanical cells. Across multiple campaigns, Woodgrove says the DFR consistently delivered higher iron recoveries and lower silica content in the concentrate. These advantages were most pronounced in the fines stream, where conventional circuits typically show inconsistent performance and greater entrainment losses. The results confirm the DFR as a platform capable of delivering meaningful gains in both efficiency and selectivity, with a direct impact on overall plant recovery.
Beyond metallurgical outcomes, the study also investigated the mechanisms contributing to these improvements. Tracer tests in the wash water system demonstrated how the DFR effectively rejects misplaced iron particles from the froth, protecting concentrate grade without sacrificing recovery. Woodgrove:“ The findings confirm that the observed gains represent more than incremental improvements- they point to a step-change in flotation technology for fine particle recovery.” Looking ahead, Vale and Woodgrove evaluated flowsheet-level opportunities for DFR applications, considering both retrofit scenarios that replace existing fines circuits with DFRs and hybrid configurations that integrate DFR units alongside conventional unit operations.“ These approaches provide operators with flexible, low-risk pathways to capture performance benefits without extensive disruption, while also enabling phased adoption of the technology.”
This joint work highlights how collaboration between Vale and Woodgrove is advancing flotation practice. By addressing the long-standing challenge of fine particle recovery through a novel flotation cell design, the DFR opens the door to higher resource utilisation, reduced losses to tailings, and more sustainable plant performance.
NovaCell implemented at industrial scale
A partnership between Jord International, Aeris Resources and the NSW Regional Government is financing the installation of the first industrial-scale NovaCell Coarse Particle Flotation( CPF) Demonstration Plant. Located at the Tritton Copper Mine in NSW, Australia, the project is advancing this innovative flotation technology for coarse gangue rejection and pre-concentration.
The turnkey 85( dry) t / h plant, designed and delivered by Jord, will be integrated into the mine’ s main operating circuit. Its design incorporates full-scale core components within a multi-downcomer system, providing a robust test for the technology viability. Sherwin Morgan, Technology Manager for NovaCell at Jord, stated,“ The installation at Tritton represents a significant advancement in the NovaCell’ s technology readiness level. The successful operation of this plant will confirm the suitability of the technology at industrial scale for coarse gangue rejection.” This demonstration project is also the world’ s first installation of a CPF technology that operates without the requirement for upfront de-sliming. By processing the cyclone feed stream and handling both coarse and fine particles simultaneously within the NovaCell, the project validates a simplified flowsheet. Morgan emphasised this point, noting,“ This project is exciting for the mining industry as it represents a simplification of future CPF circuits,” a development that promises to reduce both capital and operational costs for future mineral processing plants.
Aeris Resources’ copper mine in Australia( NSW), Tritton Operations, uses a‘ hub-andspoke’ model for delivery of ore from various sources to a central processing hub. This model offers the opportunity to leverage a portfolio of small to mid-sized regional
International Mining | OCTOBER 2025