FLOTATION as well as consumption of chemicals , water and energy .”
It says adoption of the Solvay Cube continues to grow . In a recent frother application , a Mexican lead-zinc-silver mine deployed the Cube to increase silver recovery by 9 % and improve the zinc grade by 1 % while reducing insolubles .
Health , safety and environmental ( HSE ) concerns at mines come in many forms . Solvay states : “ When a chemical is highly toxic and has a distinct odour , it may well be NaHS – or sodium hydrosulphide – one of the most controversial depressants commonly used in coppermolybdenum separation . Its toxicity lies in the generation of hydrogen sulphide gas , an issue compounded by high treatment costs and logistic challenges .” Solvay ’ s AERO ® 7260 and AERO ® NR 7361 sulphide mineral depressants can either partially or fully replace NaHS . “ As safer and more sustainable solutions , these reagents also require lower dosages while delivering equal or even superior metallurgic performance . With AERO ® 7260 , one of the biggest Cu-Mo mines in North America was able to achieve their highest production of Mo concentrate , and with AERO ® NR 7361 , another mine reduced overall treatment costs by 50 %.”
Severe HSE issues are also associated with the use of xanthates as flotation reagents . “ Xanthates are combustible , tend to self-ignite and can release toxic gases during storage , shipment and use . As alternatives with superior stability and safety , Solvay ’ s AERO ® XR xanthate replacement series collectors provide significant advantages , from ease of handling and lower exposure , to safer stock management and simplified operation . A major gold mine reduced their reagent consumption with AERO ® XR while increasing their gold recovery by 2 %.”
Another challenge can be the impact of carbonaceous gangue minerals on sulphide flotation , such as requiring higher reagent dosages , leading to cell overflows or compromising flotation kinetics . “ AERO ® carbon depressants are among Solvay ’ s robust solutions for ores with high carbon content . Besides reducing reagent consumption , they show excellent carbon depression and minimise the loss of valuable minerals to tails during flotation . In one recent case , the use of AERO ® 641 depressant on a carbon-containing copper ore resulted in a significantly higher carbon-to-copper recovery ratio as well as improved copper grade .”
“ In line with our Solvay One Planet roadmap , our mining chemistry is dedicated to providing safer , cleaner and more resource-efficient results ,” says Ricardo Capanema , Global Marketing & Business Development Director of Mining Solutions at Solvay . “ As mines manage ores with lower grade content and face increasingly stricter regulations , they can benefit from our full suite of reagents , digital capabilities and technical support to design a custom reagent scheme best suited to their flotation circuits .”
Maelgwyn and the FineFuture project
Froth flotation is arguably the most important minerals separation process . However , current conventional flotation technologies do not work adequately for fine particles , ie below 20 microns . Dr Duong Hoang , Applied R & D Lead at Maelgwyn Mineral Services Ltd told IM that this is a serious challenge at present , limiting the exploitation of deposits and proper recycling of end-of-life products containing Critical Raw Materials ( CRM ). FineFuture is an EU-funded project which explores innovative technologies and concepts to improve the flotation recovery of ultrafine particles . This three-year FineFuture project is an intensive collaborative effort bringing together 16 partners from academia and industry from 11 European and associated countries . Led by Helmholtz-Zentrum Dresden Rossendorf ( HZDR ), the project has received over € 6.2 million in funding from the EU . Hoang said : “ Besides improving our understanding of the efficient separation of fine particles by proper turbulence design . The aim of FineFuture is to combine progressive facility design and process innovations to develop new technological solutions on various TRL levels for the flotation separation of fine particles .”
He adds : " Within the context of project , Maelgwyn Mineral Services ( MMS ) is looking at utilising its innovative pneumatic reactorseparator flotation technologies for the
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 .
OCTOBER 2022 | International Mining 55