A new flotation cell that radically alters the perception of productivity
The REFLUX Flotation Cell (RFC) repeatedly demonstrates a robustness to operate at extreme levels of gas flux, feed flux, and fluidisation wash water flux, an order of magnitude beyond existing flotation methods in mining.
The ability to operate at gas and wash water fluxes above what is traditionally possible with any other existing flotation equipment sets this technology apart.
The REFLUX Flotation Cell (RFC) operates at a magnitude far beyond the capacity of existing flotation devices, reducing the required installation footprint. Its novel arrangement enhances the hydrodynamics of flotation, with the ability to recover a wide size distribution of minerals at a rate of up to 7-10 times faster than traditional methods.
This frothless system allows for stable flotation, enhanced gangue rejection, and quicker kinetics – pushing the boundaries on concentrate grade, recovery, and throughput well beyond the performance of conventional open tank systems.
The RFC is a high capacity, efficient technology capable of implementation in various applications:
Offloading overloaded flotation circuits
A single, full-scale REFLUX Flotation Cell is anticipated to provide an economical solution for industry to effectively replace ten flotation cells with a single unit, to rapidly recover valuable particles into a slurry concentrate. One additional unit should then be sufficient to fully clean the concentrate free of unwanted hydrophilic gangue particles.
K. Jiang, J.E. Dickinson, K.P. GalvinUniversity of Newcastle
Improved kinetics for fast, high-throughput flotation
The RFC combines several technologies to achieve superior flotation performance in maximising recovery, gas flux, bubble liquid segregation and product cleaning.
Recovery rates are maximised by novel contacting of floatable material in a high shear rate environment promoting elevated collision and attachment rates. The unique plenum chamberfurther promotes recovery by eliminating operation with a defined froth-pulp interface.
Bubble Surface Area Flux
Operational gas flux rates exceed what is typically achievable, increasing available bubble surface area flux by a factor of four times. Overall circuit air requirements are consequently reduced to less than 50% of traditional system demands while offering:
Improved attachment rates
Improved collision rates
Enhanced Product Cleaning
Application of inverted fluidisation water for effective counter-current washing and gangue rejection producing high grade product at elevated recovery.
Prodigious separation of loaded bubbles from slurry containing non floatable material is achieved by implementation of inclined channels allowing operation under air flooded conditions resulting in operation at:
Increased gas flux
Reduced bubble size
Energy and water efficiency
Preliminary results from pilot-scale studies indicate that RFC technology can help mines use up to 60% less energy in their flotation circuits. Improved kinetic efficiency also reduces the amount of water used in the recovery process.
Focussed improvement of flotation fundamentals
The RFC demonstrates several hydrodynamic advantages due to the unique, novel aspects of the design.
Not only fast recovery of valuables, but at enhanced grades
The RFC consists of the main vertical vessel positioned above a system of inclined channels. The inclined channels enhance the segregation between bubbles and downward flowing liquid,
allowing for operation at elevated internal gas fractions.
Feed and air are contacted in a high shear rate environment as it enters the cell via a central sparging system to expedite flotation kinetics.
The float product emerges through an annulus surrounding the sparger system, while the tailings discharge via the zone below the inclined channels.
A plenum chamber encloses the top of the cell, supplying clean fluidisation/wash water for counter-current washing of the rising bubbles with a positive bias flux to promote effective gangue rejection.