FLOTATION
applied in a particle size range from a p80 of 350 microns to 850 microns in metallic sulphide minerals but some industrial minerals processes can see particle sizes of 1 mm or more . He adds : “ In essence CoarseAir is effectively a REFLUX classifier that is utilising an aerated fluidisation system . You can look at it as a hybrid between a teeter bed separator and a flotation cell , combining a dense bed with the application of air . It includes lamella plates for much more efficient separation as well as the ability to operate with a higher degree of fines than other coarse particle flotation options in the market . Finally compared to open tank style teeter bed separators , CoarseAir offers a much sharper cut and a higher throughput by area . The testwork we have done shows we are able to take cyclone underflow material of the appropriate size distribution and feed that straight to the CoarseAir and achieve adequate recoveries and grade .”
CoarseAir is one element of what FLSmidth calls its REFLEX technology suite – which also includes the REFLUX Classifier , The REFLUX™ Flotation Cell ( RFC™ ) combines several technological elements to achieve superior performance in maximising recovery , gas flux , bubble-liquid segregation and product cleaning . CoarseAir as the name suggests goes after coarse particles ; then the RFC is a high efficiency flotation machine – “ the recovery curve is shifted , allowing production of high grade concentrate at high recoveries , while also reducing substantially the required flotation volume – five or even seven times less . And while the RFC would currently be aimed at smaller footprint cleaning circuits and scavenging applications , the technology is still suitable for large scale roughing – but of course it is a new technology so we are taking things gradually to minimise risk .”
Sustainability is also front and centre for FLSmidth , so what does the flotation part of the flowsheet of the future look like in the MissionZero mine ? “ CoarseAir will allow an increase in the grind size , with the RFC handling reground coarse material and any fine material present . That all means lower water usage plus reduced power due to not requiring a finer grind . It also means lower tailings volumes and less metals lost in the tailings ,” said Christodoulou . He added CoarseAir is at a site trials stage using a pilot machine .
The RFC he said is undergoing a full scale trial in Australia at a coal operation . “ Initial results show that the scale up from pilot scale is going exactly as predicted with flow rates twice that of conventional flotation systems .” Then looking at metals recovery there is the RFC upscaling project , supported by EIT RawMaterials with EU co-funding . The project goal is to demonstrate the superior performance of the RFC for copper and iron ore . This is an important intermediate step to the full commercialisation of the technology via consortium partners and FLSmidth .
During the project , FLSmidth says it will create and validate a profound Go-To-Market strategy including financial planning and business model developments . Phase 1 is complete , which saw feasibility studies with the RFC-100 pilot plant to narrow down design options , then engineering and assembly of the RFC-850 demo plant . Pilot work has been completed with two mining partners , copper miner KGHM in Poland , and iron ore miner LKAB in Sweden – now full size RFC- 850s have also been installed at those sites for full scale trials .
Back to the overall market – how important is retrofit versus greenfield ? For the new technologies most of the initial installs are likely to be retrofits or tailings related but as the technology becomes accepted , more of them will enter the greenfield market . Christodoulou : “ The appetite for new technologies is much greater now than even a decade ago as miners seek to maximise recoveries as well as achieve sustainability targets .”
This increase in interest is manifesting itself in much more piloting and testing – and FLSmidth is well set up for this . It has three containerised RFC pilot units that are available for site trials ; in addition to a lab pilot unit . There is also a containerised CoarseAir as well as a lab machine . On the other cell technologies , FLSmidth has six 1.5 m 3 containerised pilot cells capable of
Jameson Cell - larger volumes from smaller footprints
Jameson Cell has evolved even further in Glencore Technology ’ s trajectory for their flagship mineral processing technology to deliver more concentrate per dollar , per metre and per year . First , Jameson Cell has introduced larger-throughput 8500 / 12 model Jameson Cells in both B and Z type designs . These double the capacity of Glencore Technology ’ s previous largest cell . A single unit can treat up to 1,500 t / h . The company told IM : “ The imperative for this advancement was to create a unit that could handle the higher loads seen in large rougher and rougher scavenger duties , but the cell can be used in all duties . And as the world ’ s ores become increasingly complex and degraded , and as concentrators grow in size and required volume for processing in response , these new cells are going to pay dividends to operations that incorporate them .”
And the concept has been proven . A Z8500 / 12 has just been installed in an Australian operation . Dry and water commissioning stages have been successfully completed and the cell is performing as expected . It is set to process 2,800 m 3 / h of fresh feed slurry , which contains 1,255 t / h of solid material . Seven more B8500 / 12 units are also committed to an overseas project commencing later this year .
Second , Jameson Cell has evolved a new B8500 / 12 ERM-Less design that delivers up to 7 m reduction in height . For applications where height reduction is needed , there is potential for all B-Cell design Jameson Cells to be positioned closer to the ground . As an example , a 250-350 t / h threestage cleaner circuit can be delivered with just three Jameson Cells , in an area just 28 m long and 12 m high . The savings on building height and structural support are significant .
And third , Jameson Cell has proven that modular versions of its high throughput cell sizes are successful . “ The segmented construction is perfect for remote and transport-restricted operations . Already , two E3432 / 8 modular cells have been installed and commissioned , five modular B6500 / 24 cells have been sold , and eleven more are committed to an overseas operation under construction now .”
These innovations came as the world ’ s first Jameson Concentrator – which heavily revolves around the Jameson Cell technology – was installed and commissioned very successfully at Hudbay ’ s New Britannia operation . New Britannia was a complex two-feed project that had more talc content than initial projections and tests indicated . Two distinct ore zones deliver significant feed variability . One is a low copper , high talc ( up to 10 %) portion which comes from a low 0.2-0.5 % copper zone . The other is a low talc ( virtually no talc ) high copper (> 2 % Cu ) zone . Yet it was water commissioned within two days and it achieved tails grade target feeding a gold leach circuit within 24 hours . There are no blowers or compressors required . And it requires 50 % less footprint and power than the alternative designs . Just four Jameson Cells replace 12 tank cells .
The circuit is operating at full capacity and it is far exceeding upgrade ratios achieved during pilot tests at high copper recovery . Hudbay and its shareholders are happy with the Jameson Concentrator and are due to install a further five Jameson Cells at their Stall Concentrator
Following these successes , a major lead and zinc Jameson Concentrator is under construction providing over 50 % footprint and power savings compared to a conventional concentrator . And a total of 30 Jameson Concentrators are being considered for projects in upcoming years with individual throughputs of up to 120 Mt / y .
International Mining | OCTOBER 2022