It's a similar angle others have taken - that is the beneficiate the head grade by screening out the fine fraction. Worth noting that it's a double edged sword. Because although you upgrade the grade of the material you also lose TREO overall.
What do i mean?
If you had a circuit processing 1mtpa @ 1000ppm. You have ~1000T of TREO going in the front end to be processed.
If you're lucky as an ionic clay you might leach out ~50% as a recovery and beneficiate it to produce a 95% TREO concentrate (That's metallurgical recovery).
Not to be confused with "recoveries" using weak aqua regia which is sampling method. (Hint if your values are still in ppm then you have beneficiated jack. Post #:64189174 Post #:63174292 for the long winded explanation of that.Anyways back to my story. 50% recovery of 1000T now you have 500T @ 95% (950,000ppm) to sell.
Now let's say you opt to screen out the fine fraction.
-1mtpa processing circuit @ 1000ppm front end.
-Step 1 of process; we screen it and get ~60% of the TREO (because the rest it now out to tailings).
-Ok so of the 1000T TREO we had at the very start we reduce to 600T now before we start the processing.
-Recovery of 50% of 600T you now have 300T of TREO.
Now before others pipe in and say well what if the recoveries improve?
Well yeah they might, but they'd need to go from 50% to 83%. To get the same amount of TREO out and at more cost because now you've added screening.
Okay so why they hell are they doing it? Well ITM (proven to have ionic material) found that the calcium content was lower in the finer fraction material. So the thought process was, well because our acid consumption was high - if we screen it - maybe the recoveries improve a bit but mostly we can lessen the acid consumption rate.
Can view these screening results here and not pretty similar upgrades
https://hotcopper.com.au/documentembed?id=uOMxKKzFkiWRTLKhOROKAxjvSDYL5w67yRX2v/5t8rFiGug=Post #:
64317130 from me indicates that the fact they were doing this meant that the extractions are likely poor.
"
I think it begins to look more like a HPA play with a REO credit.To get anything substantial in revenues the front end needs to increase considerably.There's the cut of the fine fraction and the recovery loss in the leach itself.I would also think that the REO leaching would need a significant step change in overall recovery.As mentioned previously, if REO is to be primary revenue - need to hope that the composite sample contained a bunch of material outside the MRE and therefore not representative. If there's zonation within the MRE which are more ionic and you can screen the sub 45micron stuff then maybe there's a dual stream revenue opportunity - but still requires something in the realms of 2mtpa not 200ktpa.For context IXR full ramped production front end design is 10mtpa ~3800-4000tpa REO out the back end ~ 175M USD in revenue.That's a similar ppm head grade but recoveries ~40-70% across element suite.ITM would sacrifice half the REO by mass with 45um screen so would need recoveries in line with IXR and likely only result in half the REO concentrate out the back."This was due to the fact the leach tests under both neutral pH (proven factually ionic bonds) and the pH1 (using H2S04 - not HCL good luck funding that commercially) just simply had low extraction rates.
They then went and screened the product and completed secondary rounds of testing which showed no improvement and basically said we're going to focus on the graphite projects, not waste any more money drilling unless our met results in the future improve.
https://hotcopper.com.au/documentembed?id=uOMxKKzFkiWRTLKhOROKAxjvSDYL5w+7yBDxv/5t8rFiGug=So what does all that mean for MEK?
First things first - leach test with neutral pH. That tells you if you've got Ionic material present and to what degree. That's the only time comparisons to IAC's make any sense. There are only 4 projects listed on ASX that have done this (that i'm aware of).
IXR - Economically viable.
AR3 (too thin and too high acid consumption)
ABX (too thin, too deep, and too small 3mt deposit is around 3 months LoM)
ITM (strip was good and size of deposit, but not enough ionic material present - acid consumption too high)
So as you can see despite 3 other projects having ionic material present (including one i hold) they still weren't viable. Either because the strip made it unviable before you need even wonder if it will recover. (generally want deposit as thick as it is deep) if it's strip is less I wouldn't waste time as a company drilling or testing met work. Or because the recoveries achieved using economically viable leach extraction methods meant the recoveries were poor.
As for Ansto testing previously and how that correlates
i'll cite post from another post as well which shows objectivity in the response. Post #:
60986888 Post #:
61559365"Keep in mind pH is a log scale, so each single number change is 10 times the acidity. pH=3 is 10 time more acidic than 4... pH=1 is thus 1000 times more acidic than pH=4 (natural kaolinite clay pH is between 4-5 generally). This is why I shake my head when some companies proudly show off recoveries with 10% HCl (ie MEK) with a pH of -0.44 = 44,000 times more acidic than pH=4 ... shareholder ignorance really is an explorer's greatest advantage."
"MRD used ALS Laboratory’s ME-MS41W with MS41W-REE weak aqua regia digest, which they disclosed in fine print front page, Note 2," AR means Weak aqua regia acid, a mix of 1 molar hydrochloric acid (HCl) and 1 molar nitric acid (HNO3)." (pH=0 as per previous post...140 times more acidic than pH=2.4).
6A1057235_MRD.pdf (hotcopper.com.au)"Probably what's most odd/confusing to me about the decision to screen is that it's been done before the leach test? How can one know whether the course fraction of TREO is in fact 'waste'. There's 37% of the TREO by mass in the fraction about 20um. That could be the material that's ionic in nature?
Furthermore, on the drill results. Thickness needs to be same as depth. If the below are the best results 3 of them look viable based on strip. So that's if the deposit was as ionic as IXR only these 3 holes would be economically viable. The rest would have too much overburden. If you're screen out fine material, then that strip needs to be even better, or the recoveries even better.
View attachment 4890652For comparison see economical ionic clay hits.
Thickness is double or triple the depth. strip 3:1
View attachment 4890673And if curious the Scandium was 30g/t or 30ppm across the deposit. (Also ionically formed).
I think MEK market cap is underpinned by the rest of it's assets which is an excellent thing. This should just be treated as a bonus. And look that advice i needed to give myself with ITM (still hold) that the REO project isn't likely viable and that fortunately they've got some graphite and decided to focus on that. From what little i understand about the rest of MEK project suite, i believe they've got very good gold projects?
For MEK now, on this project) it would need outstanding ionic recoveries to be viable IMHO given the strip ratio it needs to offset. I'm talking like 90%+ which would be the worlds best ionic recovery rate bar none. Even then look at the recovery rates below of a viable IAC project. Most are 60-70%+. With a strip of 3:1 across most holes compares to 1:2. That means mining 6 times as much material.
Below is good yardstick for investors to reference for met extractions if and when they come. (Note - only relevant if it's a met extraction) i.e. purifying the REO and being done via an economical viable method. pH1-pH4 and using a monovalent salt lixiviant like ammonium sulphate or sodium chloride & viable acid as the dose.
Also note the poor recoveries of LaCe. Very typical in IAC's. If you leach with salt and these recovery poorly it's actually a good sign that the deposit is ionic as HREO and others tend to have more ionic material and bonded weaker.
View attachment 4890706May not be a popular opinion (as i tend not to be on ionic clay hopefuls) but i believe it to be an accurate one. I had to give myself the same reality dose on a project i bought into on the basis the RvR was good. Ionic tests proved not favourable enough.
Trust this answers your query and hopefully clarifies a few things being discussed here re the testing. Recommend people read the embedded posts to actually under this 'recovery' hoopla a bit better - few people have been stating fairly accurate comments here (not in a rude way either) and being shutdown.
ANSTO, CSIRO, ANZAPLAN, you name them. Experts indeed. They conduct the tests, and if you don't know what ones to ask for they will guide you - but just because the guide you to certain tests doesn't mean that's the best one to determine viability. Companies are generally scared to do the pH4 tests because they know if the stuff doesn't leach it ain't going to look good. Any one from those organisations or any metallurgist worth their salt will tell you that those aqua regia tests aren't a method to determine ionic bonds.
Like the Dm1 comparative sample test they done labelled as recoveries. i.e. comparing lithium borate fusion sampling against weak aqua regia sampling. Post #:
63058489 again if your material is still at ppm value less than say 100,000 (10%) it's not been concentrated. Most hard-rock target 35-45% MREC. Ionic clays target 90-95% concentrate.
To explain the fallacy around recoveries i'll use an analogy below.
-Take a large but very weak cup of hot coffee.
-999ml of liquor with 1g of dissolved coffee. 0.1% concentrate = 1000ppm (pre-processed)
-Tip it into another 1L jug - noting you leave some residue in the bottom of the old mug. (processed)
-I now have 950ml of liquor (left 50ml in the old mug).
-I measure the dissolved coffee level in the new mug and it's 0.9g. (turns out coffee settles a some got stuck to the bottom of the jug and i couldn't extract all of it by simply tipping the jug upside down)
-New ppm value .9g/950ml = 1055ppm.
-Coffee recovery = .9g/1g = 90%
I just achieved 90% coffee recovery. Let the sink in. 90% coffee recovery, anyone seen 90% TREO recovery. But note the important part... the coffee concentration it's still at 1055ppm. i.e. It's only moderately stronger. Some results might even be less ppm than the were prior. (See embedded post from Dm1) testing "weakly bonded material"
If you're not concentrating the desirable elements meaningfully the recovery value is useless.
The intent is to extract the 1g of coffee in it's pure form.
You want to end up with 0.5g of coffee in 0.55ml solution. (i.e. boil off all the water and see how much coffee grains you can keep).
That would be 0.5g/1g = 50% coffee recovery
and concentration 0.5/0.55 = 90% concentration level or 900,000ppm.
This is a simply analogy for TREO recovery vs TREO met extracting.
Now just pretend there is 17 different brands of coffee in that cup and they're all worth different amounts. That's rare earths.
Long winded as always - sorry for blabbering on but like to be comprehensive in explanations.
SF2TH
