Not a problem.
Yes I hear you, and at the risk of going off-topic, it’s been an interesting year – with the amount of “new” or “significant” REE clay discoveries….. jumping on the ion adsorption clay REE (IAC-REE) bandwagon.
If you take a typical granite rock - weather it in the right environment, you will develop a “significant REE clay”
For me, there is still a massive difference between any of IAC-REE results being announced recently and what DRE is uncovering at Mangaroon (not just in terms of grade, but also in terms of scale potential and deposit fundamentals).
DRE is on the verge of what could be a truly world-class REE mineralised system…there have been many good discussions on here previously, so I won’t bother re-hashing that.
Don’t get me wrong, I think the IAC-REE deposits do have potential, but they come with a very different set of challenges to what we are dealing with at Mangaroon (not saying we won’t also have challenges, just different).
The main advantages (at least what’s often promoted) of the IAC-REE deposits is lower capital intensity from cheaper mining methods (free-dig vs drill and blast) and cheaper extraction because the REE are physically adsorbed to clay minerals via weak electrostatic forces so they can be recovered with dilute electrolyte leaching processes (in-situ, batch, or heap). In theory that’s great – but then there is a distinct lack operating IAC-REE mines outside of China and Myanmar, Serra Verde in Brazil is about the only example I can think of.
Probably one of the more advanced IAC-REE projects in Australia right now would be AR3’s Koppamurra with 39.9 Mt @ 725 ppm TREO. Certainly not having a go at AR3 at all, just that they have a resource and a more advanced flow-sheet to work from. Overall, the 725 ppm (0.0725%) TREO contains 17.3% Nd2O3 and 4.4% Pr6O11 with recoveries of TREO ranging from 45 to 68%.
So, in that case dealing with a much lower TREO plus NdPr:TREO ratios of around 15-20% (but potentially much lower extraction costs) compared to Yin which is looking like TREO grades somewhere between 1 and 2.5% (localised pockets of higher grade) with NdPr:TREO ratios of 20-35%.
Also, at the exploration stage, the TREO results we see/read are generated by commercial laboratories - either via strong acid mixtures or fusion i.e. REE’s occur in minerals that are resistant to weaker digestion methods. So, what I mean by that is if you submit a handful of clay to ALS to analyse for REE analysis by ME-MS81 or ME-MS61, then sure you get a relatively accurate determination of REE concentration. But, it tells you nothing on the proportions of REE that are weakly bonded to clay minerals vs resistant REE minerals in regolith (i.e. placer style). So how that ‘clay’ or regolith material responds to a much weaker lixiviant (sodium chlorite, ammonium sulphate solutions etc) may be very different.
With continued REE demand I can certainly envisage some Aus based IAC-REE deposits eventually being bought into production throughout the next decade, mostly I assume as staged strip - heap or tank leach – reclaim/rehabilitate style operations. Similar to the mineral sands and bauxite style operations, I’m not so sure we will see the in-situ leaching style operations. But IMO they will be few and far between – at least compared to the number of ‘new discoveries’ coming out over the last year or so.
I guess its no different to other exploration, in that it really comes down to DYOR…..I just feel the ionic clays are on another level of DYOR.
Expand
(20min delay)