FLSmidth has developed an inspired flotation solution for the mining industry, delivering drastic improvements across all key metrics.
The REFLUX Flotation Cell (RFC) is reshaping flotation technology as we know it, offering substantial improvements in recovery rates, energy efficiency, and water savings.
The innovative flotation machine, developed by global mineral processing pioneer FLSmidth (FLS), operates in a frothless environment, delivering significant efficiency and sustainability benefits for mining companies.
Lance Christodoulou, FLS global product line director – REFLUX Technologies, spoke to Australian Mining about the RFC’s cutting-edge design, its advantages over traditional flotation methods and the impact it is having on mining operations across the world.
Unlike conventional flotation tanks that rely on a froth layer to separate valuable minerals from waste, the RFC eliminates the need for froth, instead using a high-volume bubbly mixture. This enables operators to separate minerals more effectively.
“The REFLUX Flotation Cell is a high-intensity flotation machine,” Christodoulou said. “It delivers staged flotation in a frothless environment, so there’s no discernible froth pulp interface.
“The machine contains inclined channels in the separator to help segregate the bubbles from the liquid – a novel approach that mitigates common issues with traditional flotation cells, such as froth breakage, drop-back losses, and stagnant zones that hinder recovery.
Image: FLS
“All open tank flotation machines have a froth layer and a pulp layer. When the bubbles pop, valuable material can be lost, but with the RFC, there’s no risk of froth breaking or bubbles being disrupted by washing effects.”
One of the standout advantages of the RFC is its impressive recovery rates and kinetics improvement.
Traditional flotation methods often require extended residence times for adequate separation, whereas the RFC delivers much faster results.
“We operate with very high gas fractions – around 45 to 50 per cent air by volume – and very small bubble sizes,” Christodoulou said.
“This creates a much higher bubble surface area flux in the machine, significantly increasing recovery rates.
“We’ve seen applications where it’s up to 10 times faster in terms of kinetics. If you need 10 minutes of residence time in a traditional flotation setup, you only need one minute with the RFC.”
This increase in processing speed means mining companies can achieve the same output with a significantly smaller flotation footprint, reducing capital and operational costs.
The RFC has demonstrated success across a range of mineral applications, including copper, gold, lead, zinc, nickel, potash, graphite and coal.
The technology is not only limited to specific ore types, but also excels in various flotation applications, such as scavenger, rougher and cleaner circuits.
“In scavenger applications, we see a major footprint reduction,” Christodoulou said. “The RFC shifts the grade–recovery curve, which means we can process more material using significantly less space.
“In rougher applications, we can produce a much higher-grade concentrate, which reduces the need for multiple cleaning stages.”
By reducing the number of cleaning stages, the RFC simplifies the flotation process, lowering costs while maintaining – or even improving – product quality.
With the mining industry under increasing pressure to reduce energy consumption and improve water efficiency, the RFC is delivering substantial savings in both areas.
Image: FLS
“The high kinetics of the RFC means material moves through the system much faster, so we require a much smaller footprint,” Christodoulou said.
“We don’t have a direct mechanical mechanism driving the flotation process – it’s all hydraulic – so energy consumption is reduced by 30 to 60 per cent compared to traditional flotation systems.
“The water savings are also significant. If you look at a conventional column flotation cell, you need a large amount of wash water to maintain efficient product cleaning.
“With the RFC, because we reduce the flotation cross-sectional area, we can achieve up to 70 per cent savings in air and water supply.”
The RFC has already delivered impressive results in mining operations. One notable case study involves a copper concentrator, where FLS conducted extensive testing on the rougher, scavenger and cleaner circuits.
“The copper plant required about 30 minutes of retention time, but we were able to achieve the same results in just three minutes,” Christodoulou said.
“The client was so happy with the results that we’re now working with them to implement a full-scale RFC at their operations.”
Such outcomes highlight the real-world impact of the RFC, demonstrating its potential to transform mineral processing operations.
FLS works closely with its clients to install and optimise the RFC for specific mineral processing environments, including after-market service.
“We provide full support from commissioning to overseeing installation,” Christodoulou said. “We also have a team of site service personnel available to assist, and I personally stay involved to ensure a smooth transition for all RFC installations.”
As the RFC makes waves in the mining industry, FLS continues to refine and improve its design.
“We’ve already made some mechanical design adjustments based on industry feedback, and as the product matures, we’ll continue to optimise it,” Christodoulou said. “But I don’t see a fundamental change in the product’s approach because it’s quite unique and novel in the flotation industry.”
Christodoulou also sees a broader shift in the mining sector, with companies becoming more receptive to new flotation methods.
“There are multiple new flotation technologies emerging, and all of them are gaining traction,” he said. “It’s great to see the industry moving forward and exploring better alternatives to what’s been done for the last 100 years.”
Beyond efficiency gains, the RFC plays a key role in improving sustainability outcomes. By extracting more valuable material from ore, it reduces waste and improves overall resource efficiency.
“The flotation technology is very efficient, so we’re getting much more out of what we put in,” Christodoulou said.
“With higher recoveries, we’re ensuring that valuable material isn’t lost and wasted.”
With its groundbreaking approach, high efficiency, and sustainability benefits, the RFC represents a significant advancement in flotation technology.
As mining companies worldwide continue to seek smarter, more cost-effective solutions, the RFC is proving to be a key innovation that meets both economic and environmental demands.
Backed by FLS’ commitment to support and continuous improvement, the RFC is well-positioned to drive the future of flotation technology and help mining companies optimise their operations for years to come.
This feature appeared in the April 2025 issue of Australian Mining.