FLOTATION
DELKOR ' s flotation progress
TAKRAF Group company DELKOR is making rapid progress in froth flotation . DELKOR ' s MAXGen mechanism was developed through research and testing at various levels , including a simulation and computational fluid dynamics study of 72 models of rotor and stator mechanisms .
DELKOR ' s operations in Australia have been at the forefront of flotation success for some time now . Recently , DELKOR Australia has completed the supply of flotation cell banks to a gold mining company in Australia which will start production soon . An eastern European client commissioned their Phase 1 copper project using DELKOR ' s MAXGen flotation cells , which delivered superior performance by producing higher grades and yields . This particular site has 23 flotation cells of various sizes that have been in operation since 2023 .
A major iron ore mining company in India entrusted DELKOR with a pilot scale modular flotation plant to test the iron ores for future expansion of iron recovery . Banded iron formations are one of the most complex ore bodies to treat due to the disseminated iron content in the ore body . Due to its complex structure and liberation size , the ore needs to be finely ground to recover the valuable content . Although the iron ore market has not yet reached a situation where these banded iron formations need to be mined , thanks to large resources in India and Australia , it is expected to attract significant interest from mining companies in the near future .
cells . But Eriez customers had some new ideas too – if you had a 600 micron tail then it is much easier to dewater as it is sand instead of slimes – Anglo American have taken this to full pilot scale with its Hydraulic Dewatered Stockpiling ( HDS ) at El Soldado . It requires a lot less energy to recover the water – a major factor in high tonnage operations in arid regions – El Soldado can now recover over 80 % of its tailings water . HDS is also being piloted at Mogalakwena . Both are using HydroFloat demo plants . These stacks are far more stable than conventional wet dams and consolidation of the material is faster meaning the rehabilitation of tailings facilities can also be carried out more quickly .
Some of the major EPCMs have also recognised that CPF is a niche that will enable them to get a competitive advantage by becoming early adopters and leading early proponents . This includes Ausensco , DRA and Hatch for example , who all have specialists now in this technology – they can offer the conventional approach but also do trade off studies with CPF for customers .
Wasmund : “ One thing worth consideration is that head grades are decreasing – mining 0.3 % copper ore versus 0.6 % means you are processing twice as much rock to get the same metal content . And that doesn ’ t include additional the stripping that might be required . In this context producing tails as sands instead of fine slimes is a huge long term legacy benefit . Beyond the business case benefits , we also are starting to see water recycling and recovery becoming an important consideration in permitting in some jurisdictions .”
Strategically as well , the mine owners are the ones who have to take the risk in going with new flotation technologies but more of them are doing it and recognising that flotation does not just have to always mean large stirred tanks with a launder on top . “ There are several new technologies in flotation today that along with us mean that it has become a much more competitive marketplace and that is driving a lot of innovation . And now we have references , these are being visited all the time by corporate groups and project teams from major mining houses plus the EPCMs – all this is driving progress . Of course miners like to have a first mover competitive advantage but mining companies today recognise the value of the whole industry moving forward together and the sharing of mutual knowledge and benefits . This is exemplified by our group at the University of Queensland – which has been running for almost five years - it is no longer Eriez talking to one miner – we are all in the room together and we are acting to facilitate discussions between the operators . They know a lot of the intended and unintended consequences of adding CPF to a flowsheet which as a technology OEM we may not necessarily have been fully aware of .”
There are many greenfield copper projects as well as brownfield expansions of existing plants in play today , and Eriez is involved with many of them in assessing the applicability of CPF including a lot of piloting and lab work . “ We have a whole pathway which works like a stage gate process where you can start with a 100 kg amount of ore or tails to see if there is potential and the likelihood of the recovery you would get . If it works at lab scale we can move to a pilot phase and send one of our pilot units to site . It is fully modularised and we can run it for one or two months or longer , depending on the customer goals . We know then it works for their ore feed and plant variability – and could then progress with an engineering partner to a study
and then a demo plant and potentially finally a commercial installation .”
Eriez has its own dedicated test lab in Pennsylvania but a lot of testwork is done by independent lab services companies globally that are certified by Eriez who also oversee the work . Wasmund : “ This is done so we don ’ t become the bottleneck as would be the case if all of the tests had to come through us . Using a third party lab also removes any perception of bias in results , though we would say our own lab tests produce as good if not better results than elsewhere . It is the customer choice . Often it may just come down to logistics where it was easier to not have to ship a sample out of a country or region .”
A good example of a potential new large commercial user of HydroFloat is Glencore ’ s Antapaccay , which has stated via technical aspects of detailed Environmental Impact Study for its US $ 200 million plus Antapaccay Tintaya Expansion-Coroccohuayco Integration Project that its intention to build a large CPF plant to treat tailings from the conventional flotation circuit and recover coarse particles with copper content , while the plant throughput will remain at 100,000 t / d . The EIS states that project will be developed using Eriez HydroFloat cells . The CPF plant will be composed of primary classification modules , HydroFloat modules and a regrind module ( consisting of a ball mill ), where the rougher-scavenger flotation tailings from the concentrator plant will be treated .
Finally , a note of update on the Eriez-Weir collaboration that was announced in 2022 where both companies said they would closely work together to design and develop revolutionary coarse particle flotation ( CPF ) systems to advance mining operations throughout the world . “ We only offer a few specific technologies and some mining groups like to deal with a more onestop shop type of vendor which has sometimes meant we have lost out on tenders . Weir has many complementary products and many of those which can be used to perfect the CPF flowsheet including HPGRs on the comminution side as well as pumps and cyclones on the process side as well as high tech wear materials . We work with Weir right from the pilot stage using our equipment and their equipment . So when we scale up we know the whole flowsheet works .”
This de-risks the scale-up from the customer perspective because you are scaling up the same equipment types throughout . It also offers the customer the opportunity to go best in class when you look at energy and footprint . In addition to Weir , Eriez works closely with another of its partners , Swiss Tower Mills ( STM ), as their vertical stirred mills can be used to regrind concentrate for CPF . “ At Weir ’ s facility in Venlo we have brought together the HydroFloat with a STM mill plus Weir HPGR as well as hydrocyclones and other equipment all at a smaller scale to come up with the best solution on behalf of the customer .” Weir and Eriez have already partnered
OCTOBER 2024 | International Mining