SEPARATION & CLASSIFICATION
Simple flowsheet of the CiDRA P29 technology process where each of the unit operations are performed with industry standard equipment
plant becomes more efficient with higher recovery .
OZ Minerals and CiDRA recently commissioned a front end engineering and design ( FEED ) study for a full-scale implementation of CiDRA ’ s Grind Circuit Rougher technology at the Carrapateena mine to remove coarse material from the grind circuit circulating load , enabling an increase in plant throughput . Worley , a global project delivery and asset service provider , will provide front end engineering design services ( FEED ) for the project . OZ Minerals is an ideal lead customer for GCR as the mining company has long been known for being open to innovation . An additional agreement covers a demonstration plant at OZ Minerals which other miners will be able to come to and review . CiDRA is also working with a couple of copper majors who are keen to look at how P29 can help their mines increase their throughput and maximise recovery .
Maron adds : “ For several years we have been doing campaigns of laboratory tests for a number of mine operators – many of them in Chile given the size of the copper industry there . GCR has been proven in the field at both a lab scale and at a pilot scale , though the successful field pilot happened to be in a scavenger application where P29 also works well , it is just that the greater value proposition is in its use with GCR .”
IM also spoke to Mark Holdsworth , now CiDRA VP Application Development but previously having held numerous mineral processing excellence and innovation roles at Rio Tinto over a 22-year career with the global miner . He commented on P29 : “ P29 can replace flotation so it is no exaggeration to say that it represents a new branch of mineral separation . It is also engineered so we can optimise collection , transport and recovery independently . The launch GCR application has the ability to reduce grind energy by up to 50 % because it can recover such large coarse particles . The P29 process has a very short retention time , low mass yield and high upgrade ratio . In terms of the future path ,
right now it is tuned for anything you can recover via sulphide flotation but because it is effectively a solid to solid interface we have the potential to do R & D chemistry to enable recovery of minerals that cannot currently be recovered via flotation today and therefore unlock previously uneconomic orebodies . Flotation is limited by reagents that have to be dissolvable in water and this really limits your chemistry scope . P29 has the potential to selectively recover or significantly reduce entrainment of deleterious minerals that are associated with copper in many major deposits . It is not a leap to say that P29 will be an important part of the concentrator of the future – less energy , less water , better water recovery , and engineered recovery mechanisms on metals bound up in minerals that aren ’ t economic today .”
This novel technology has been specifically designed to help address many of the critical challenges facing the mining industry and is covered by a broad patent portfolio of the core P29 technology and its application space . Lower head grades , harder ore , rising energy costs , scarcity of water , forecasted base metal supply deficits , and the drive towards greener mining is forcing the industry to adjust . P29 has the potential to unlock the copper that the world needs , particularly to feed electrification via battery power .
The foam substrate can be engineered with different pore sizes and the media can be tailored for the particle size distribution for the specific application . The pore size in the media defines the available surface area for mineral attachment and is analogous to the bubble surface area in froth flotation . The advantage of engineered foam media as a mineral collection mechanism is that it can be optimised for durability , surface energy , compliance , and flexibility , as well as the shape and size of the media . The industrial reticulated foam is coated and cured through industry standard processes ; the cured foam sheets are then cut into cubes and vacuum packed for shipping .
The contactor is a simple mixing device designed to contact the mineral slurry with the collection media . Embodiments of the contactor
are a sump / pump and pipe or a horizontal rotating drum . The circuit configuration will be a function of the feed slurry mineralogy , rheology and application space . The loaded media is separated from the slurry via a screen , either attached to the end of a horizontal drum contactor or as a standalone vibrating screen . A recycled water rinse is used to remove the entrained gangue from the media which results in high upgrade ratios and low mass recoveries . The media is dewatered prior to the mineral removal stage with either a vibrating screen or a ‘ low g ’ basket centrifuge . The mineral is removed from the media by passing the loaded media and release agent through a series of disc pumps . The release agent used in the mineral removal stage is reclaimed using a centrifuge or nano filtration stage . The reclaimed release agent is returned to the process .
Its potential application space is also impressive . P29 can be applied to any current froth flotation application and importantly operates with a wider operating window than froth flotation-based technologies , most noteworthy at a very coarse particle size with no feed preparation requirements . This versatility in operability enables an ESG friendly technology platform with a broad application space such as in existing operations with GCR but also as part of brownfield expansions , coarse flotation scavenging , flotation tails scavenging , cleaner scavenging and tailings reprocessing . It can handle a wide range of particle sizes at high percent solids with minimal feed preparation . In greenfield mines it can radically decrease the footprint , water usage and power requirements with a coarse tail plus marginal deposits become profitable .
Ultimately P29 has the potential to deliver an extra 3 Mt / y of copper with the existing grind circuit assets currently installed across the mining industry , or about 50 % of the predicted 2030 supply deficit . This is delivered by the ability of P29 to recover coarse particles from the grind circuit circulating load at traditional flotation recoveries unlocking energy in the grind circuit that can be utilised for increased throughput and / or reduced grind size , thus reducing the grind specific energy and carbon footprint of a ton of metal produced . Coarse particle recovery with a throw away coarse particle tails stream unlocks increased water recovery from the plant tailings , significantly reducing the water requirements for the mine . A coarser tailing also enables new and safer designs in tailings impoundments and in a greenfield application tailings could be dry stacked , eliminating the need of a tailings dam . The reduction in energy and water requirements per tonne of metal produced results in a potentially reduced carbon footprint , and in a
14 International Mining | MAY 2023