FLOTATION
The FLS RFC is now seeing increased interest across metal sulphides and industrial minerals- this shows a full sized cell trialled at KGHM’ s copper operations in Poland
Elsewhere, at a major southeast Asia copper mine, a 2 m RFC( RFC2000) was part of a successful pilot trial for processing smelter slag tails and cleaner scavenger tails, assessing potential recovery improvements.
Another example in copper is with BHP at Carrapateena, where a RFC was tested alongside a Glencore Technology Jameson Cell. This work was presented in a paper at MetPlant 2026. Carrapateena conducted a pilot test program with the RFC and investigated its effectiveness at rejecting fine non-sulphide gangue( NSG) without reduction in copper recovery. This was in a cleaner-scalper duty. The RFC was found to recover copper at an equivalent rate to the existing plant whilst reducing entrainment of fine non-sulphide gangue by approximately 50 % in fine size fractions. Flotation tests of the RFC concentrate resulted in no meaningful increase in copper grade, indicating concentrates produced were near the maximum grade achievable by flotation.
Considering the promising results from the pilot plant, BHP and FLS agreed to demonstrate a 2 m diameter RFC( RFC2000) at Carrapateena. The RFC2000 is now being delivered and installed later this year and will increase the capacity of the cleaner circuit, resulting in modest increases to overall recovery and concentrate grade.
There are also now commercial installations of the RFC – namely at a US industrial mineral mine operated by a global industrial minerals producer. It selected multiple REFLUX™ Flotation Cells( RFC™) for service in a reverse flotation application. FLS:“ In this challenging duty, silica is removed to produce a high-grade product. This milestone is the culmination of lab testing, pilot testing, and a full-scale industrial trial. One RFC™ has the capability to replace a row of up to ten conventional cells, significantly reducing the flotation plant footprint as well as operating and maintenance costs.” FLS added:“ Reducing OPEX on a duty like this takes a real partnership. Many thanks to the customer’ s team, who know their process and have tested our technology thoroughly. That work continues together, backed by our process technology expertise and lifecycle support. Partnerships like this turn innovation into the trusted standard.”
Moving to FLS CPF technology, coarseAIR is based on the REFLUX Classifier( RC), a highly efficient fluidised bed separator widely adopted in the mining industry to improve fine particle recovery. The coarseAIR solution combines the hydrodynamic advantages of the RC with the selectivity benefits of flotation to float larger particles than conventional flotation processes, which are typically limited to particles of-200 μm.
The coarseAIR cell operates as an aerated fluidised bed separator, where coarse particles are floated without the high levels of agitation seen in conventional cells. This helps to prevent bubble-particle detachment seen with coarse particles in traditional systems. At the same time, the fluidised bed acts as a semi-permeable layer, avoiding the loss of bubble-attached coarse particles to the underflow.
Christodoulou:“ The coarseAIR is a more recent introduction than the RFC, but we have already run some test campaigns in feldspar, where we’ ve shown that we can recover coarse particles very efficiently. We have improved the circuit performance for that specific operation, and we are talking with them about how to implement the technology at full scale in the circuit.”
He adds:“ We’ ve also got another application in potash that we’ re going to trial in the coming months where we’ re targeting coarse particles, and doing a kind of split float where we’ ve got conventional cells going after the-300 to-400 micron material and the coarseAIR going for the + 400 micron material. We are currently waiting for those pilot results which should be forthcoming in the next couple of months.”
Looking at coarseAIR and sulphides, including copper, Christodoulou said that a number of tests have also been carried out.“ This included a tailings stream, where we took the feed of about 0.065 % copper and were able to recover between 60 and 80 % of the copper on that stream, taking it down to 0.028 % copper in the tails with the coarseAIR. Looking at a tailings treatment module, which includes a regrind mill plus coarseAIR pumps and sumps, depending on how we run it, the payback period for that module would be as little as six to eight months. So, the economics are pretty strong.”
Eriez and HydroFloat coarse particle flotation
Mining companies are under increasing pressure to produce more metal while reducing energy consumption, water use and operating costs. As a result, there is growing interest in technologies that can improve resource utilisation without relying solely on finer grinding and additional comminution capacity.
International Mining | OCTOBER 2026