FLOTATION
Westpro ' s proven potash solutions
Looking at potash flotation specifically , it has charted its own course . The value of potash products is directly linked to particle size , with coarser products selling at a premium . Canada ’ s Westpro Machinery told IM : “ Potash flotation isn ' t a one-size-fits-all operation . Applications range from rougher flotation to different stages of cleaner and scavenger stages . Although most plant flotation circuits share similarities , each is customised to suit the specific ore being treated .” Given the operations ’ diversity and scale , Westpro ' s proven potash flotation technology it says has shown to be effective and economical . The cells are tailored to meet the specific process requirements of each project . Notably , the FL300 cell series has gained significant popularity in potash applications , with installations in numerous projects around the globe . “ Additionally , Westpro has been at the forefront of coarse and fine particle recovery through its innovative W19 flotation technology in recent years . This new technology has significantly enhanced the mixing capacity of the rotor , accommodating a wider range of particle sizes and leading to substantial power savings . Implementing the W19 mechanism in tank cells has resulted in clearly well-defined mixing , quiescent , and froth collection zones along the tank ' s height . This has reduced sanding issues and maximises particle-bubble interaction thanks to improved mixing and air dispersion at consistent aeration rates .” Westpro says its equipment is manufactured to the highest Canadian standards in components that require minimal on-site assembly . Supply has ranged from individual components to complete modular circuits .
instruments and blowers ensure precise air distribution for enhanced process control and flotation optimisation , elevating mineral processing efficiency .”
Moving from fines to coarse flotation , what is Metso ’ s current strategy there ? “ This is something we like others have been working on internally for a number of years and I would say in the next 6 to 12 months we will be ready to start sharing some of our coarse particle flotation findings and results as we already have a lot of data , including using customer ores . We have evaluated several concepts that resulted in us going right back to fundamentals to decide on the most efficient design possible . Keeping it compact and simple was a big part of this as was removing the need for auxiliaries and keeping water consumption as low as possible . A launch is still some way off but within the next couple of years , however , we are waiting until we get to quite an advanced stage before we do that . Also even the existing options in the industry have mainly been used at pilot scale – we want to be able to offer a full scale plant solutions based on coarse particles .”
Rinne added that there is also further evolution of its mechanism technology - Metso ’ s evolutionary journey has already led to the development of game-changing solutions like FloatForce ® . Launched in 2005 , FloatForce represented a new generation mixing mechanism , significantly enhancing flotation hydrodynamics . By maintaining optimal mixing at higher air dispersion rates , this inevitably results in improved metallurgical performance . “ We have been working with the next iteration of the FloatForce design – it has led the market for almost 20 years but we believe we have been able to further improve on it – more details will be shared soon .”
Sticking with internals , froth launder modernisations such as Metso ' s Center Launder upgrade have been proven as a solution to overcome poor froth recovery in operating flotation cells that suffer from high froth surface area . However , lower head grades and even larger mechanical flotation cells can still result on stagnant froth zones and inadequate froth collection in the cells that already equipped with advanced launder and crowder such as Center Launder design . This calls for developing next level of froth management upgrade product to provide even more crowding in extra-large cells or for very low-grade flotation applications . Metso has developed a newer crowding scale-up advancement - the Spider Crowder Upgrade - to be utilised on top of exiting Center Launders to maximise froth recovery .
FLSmidth ’ s REFLUX™ suite plus WEMCO II
FLSmidth has created a whole product line , now called REFLUX™ Technologies , which groups together four different separators , all managed by Lance Christodoulou , the Global Product Manager for the range together with his team . It consists of the REFLUX™ Classifier ( RC™ ) – a gravity-based fluidised bed separator ; the REFLUX™ Concentrating Classifier ( RCC™ ) – a modification of the RC ; the REFLUX™ Flotation Cell ( RFC™ ) – an advanced high efficiency flotation cell ; and coarseAIR™ , a coarse particle flotation machine
Each of these products have had highlights over the past 12 months or so . Christodoulou told IM : “ The RC has seen a great level of adoption in the iron ore industry , where the performance
efficiency of the RC has shown to produce high grade concentrate at elevated solids concentration replacing traditional methods of beneficiation .” He adds : “ We are in the process of launching a new separator called the RCC which is a modification of the RC designed specifically for recovery of high value low grade ores . This gravity separator has shown to be highly efficient in upgrading in applications like tin and tantalum amongst others .”
The RFC technology has an entirely new internal design which results in much higher throughputs whilst simultaneously separating smaller particles in a more efficient method that improves gas bubble control . Consequently , flotation cells can be much smaller for given separation tasks and / or a much lower number of tanks are needed to operate in series ( one or two tanks only ).
The commercialisation of the RFC has gained upscaling momentum with FLS securing its second installation of an industrial unit with a major copper miner at one of its concentrators , based on successful pilot-scale testing of the RFC-100 at the same location . Performance of the industrial machine , the RFC-850 , is outperforming the pilot scale equipment in terms of required retention time . “ Substantial pilot and lab testing has been ongoing with results showing that the RFC is delivering as a high efficiency flotation technology . Testing has consistently shown that reduced retention time is needed with the technology shifting the grade recovery curve .” Poland ' s KGHM confirmed it was the company testing the RFC in its Integrated 2022 Annual Report , saying that its ore processing optimisation tasks in 2023 included “ conducting tests at an industrial scale of RFC flotation machinery .”
A number of pilot testing campaigns have been conducted in cleaning , scavenging and rougher applications across various commodity types including including copper , molybdenum , gold , graphite , nickel , potash , limestone , iron ore and coal .
Lastly , the development of FLS ’ coarse particle flotation machine , the coarseAIR , has
The RFC-850 industrial test skid
34 International Mining | OCTOBER 2023