1. Summary
I actually was going to post in LTR again but thought the better of it. I tend to agree that the move to Whole of Floatation over there is either caused by:
1. Difficulty in removing deleterious elements in say a DMS circuit, or
2. LTR is targeting higher grade product that DMS cannot produce, and here I am thinking both technical and chemical grade product is what LTR is targeting - i.e. producing grades through floatation of 6.5% Li20 plus. It is this point 2 that i am thinking is the reason btw, not point 1 btw.
See you received the same cold shoulder as well.
I wasn't going to comment on your posts here or there but decided I should as ultimately companies are using different approaches in pursuing the making of 6% grade spodumene etc - some relying wholly on Whole of Floatation (LTR/MLL), others only DMS (GXY) and others a DMS/Floatation option (AVZ/AJM/Mt Marion, the former KDR). Greenbushes is also DMS/Floatation, but its last expansion seemed to be WOF. Point is, what works is what works for you and what you are seeking to achieve and what markets you may be seeking to target.
2. Whole of Floatation versus DMS/floatation
I found the whole debate over there weird to tell the truth, given it started from this post and went of track IMO from there to only high grade ore uses Whole of Floatation - Post#: 45112889 - noting this was the opening line in the link in that post but somehow the discussion became only "Whole of Floatation" is used for excellent grade deposits and DMS/floatation for the dreggs, a laughable concept - Despite, in effect, AJM/PLS/MIN actually having floatation attached after DMS btw.:“The ore reserves have been depleting with mines goingdeeper. With growing need to process more and more ore, coupled with stringentregulations for a cleaner production of metals, the mining industry is lookingfor more efficient and sustainable recovery solutions such as WOF.”
What does that paragraph mean too me – more ore, read lower grade, makes whole of floatation a more viable option. The key word is "such as", meaning in the past some were doing something else (and presumably at a lower cost, but as grades reduce WOF is seen a better option).
The answer is I suspect LTR are targeting other markets than just batteries IMO, but your suggestion that maybe it is more difficult getting the deleterious elements from the ore is a possibility, albeit I don’t think that is what is driving their approach. Greenbushes produces technical grade product above 6.5% Li20, and some above 7%, so suspect floatation is going to be a lot easier to produce those types of grades than DMS (where you can have a lot of wastage in DMS for producing spodumene above the most optimal configuration - removing say an additional 0.1% Fe203 via say DMS, where it is hard/to impossible to remove impurities inthe lattice of the spodumene, makes you lose a greater percentage of spodumene in that recovery.As you know, DMS doesn’t adequately deal with impurities in the lattice which I have posted about previously.You either can produce chemical grade spodumene with the appropriate specs at DMS at a viable cost of extraction or you can't (and therefore need floatation) or you don’t want to because you want to produce a much higher grade product.
Forthe record, if something grades 1.5% Li20, what is been said is 20% of the orebeen milled is spodumene.That is why DMS/floatation is viable.Nice percentages to work with in DMS btw, 1% copper in ore equals DMS only not viable IMO, as 1% means something different when comparing headline grade of copper/nickel and spodumene.
Alsowhen you say a concentrate is 6%spodumene concentrate you are also saying 75% of that concentrate is spodumene btw as well as SGS itself also notes, -https://www.sgs.com/~/media/Global/Documents/Flyers%20and%20Leaflets/SGS-MIN-WA109-Hard-Rock-Lithium-Processing-EN-11.pdf - and I went through many of these conversions some time back for those whowant to understand numbers such as how many EVs one tonne of 6% grade spodumene serves - Post #: 40855132: That is also very different to a copper (or nickel) concentrate where generally 30% of the concentrate is copper.
3. Relevance to AVZ
A lot of this section taken from various posts of mine.
Given AVZ is going DMS/floatation at some point, as is the former KDR who has a better grade in the MRE for the DFS than what LTR will have btw based on its MRE (despite LTR having better grades at depth), I'll make some other comments as well - it is the coarseness of the spodumene, not grade, and how easily removed it can be from the lattice of the spodumene that makes DMS viable or not. Nothing to do with grade, albeit grade is important overall to project economics.:
When talking deleterious elements there are three main types you don't want - phosphorous (P), fluorine (F) and Fe (iron) especially. these are essentially your penalty elements, including some of the ones below in pricing spodumene - the spodumene needs to keep these in check or you have the clinkers effect. The key thing you are really focussing on is fluorine and iron, because fluorine and iron is an element of mica. The other is magnesium (Mg), potassium (K) and calcium (Ca). I should say here, feldspar and quartz may also contain impurities you don't want as well, so the key is around liberation as well in crush sizes etc.
Spodumene formula is: LiAlSi₂O₆
You can get the Mica formula here:
https://en.wikipedia.org/wiki/Mica
Quartz formula here: SiO2
Feldspar formula here:
https://www.britannica.com/science/feldspar/Chemical-composition
Feldspar = specific gravity - 2.6, spodumene SG = 2.8 - 3.0, quartz specific gravity = 2.65 and mica specific gravity 2.76.
The point of the above, is when you look at the formulas you can certainly see which aspects of the rock/pegmatite/gangue some of the impurities come from, but others can come from a couple sources and then you have to think of likely source. Given the SG of micas are close to spodumene their removal is the hardest so some of the key impurities originate from micas (and that is why micas are particularly looked at in my opinion). There removal by and large at the DMS stage is really based on large coarse crystal sizes that ineffect allow for spodumene liberation in order to minimize lithium losses to the float product. If can't do that, then floatation becomes the only option by grinding the ore to a pulp.
This patent - https://patents.google.com/patent/US2748938 - gives an idea as to mica removal etc in floatation. As does this explanation of mica removal in preparation and floatation - https://www.911metallurgist.com/blog/froth-flotation-spodumene-processing-lithium-extraction
AVZ clearly appears to be able to deal with producing a decent coarse product in the DMS circuit -, albeit to get to an over 80% recovery rate it will need to have DMS/floatation option btw. I doubt AVZ can produce the higher end products in DMS such as 7% Li20 (i.e. anything destined for the technical grade market been ceramics etc requires even lower deleterious elements than chemical grade product) without substantial losses in spodumene. It certainly can produce chemical grade spodumene - i.e. the 6% grade for the battery market - within specs. Having said that, I can't recall AVZ suggesting in the past it had plans to also supply the technical grade market as well - note technical grade product can be used in chemical grade applications but not vice versa.
Finally, here is an abstract of a paper presented at Extraction 2018 - Proceedings of the First Global Conference on Extractive Industries - https://link.springer.com/chapter/10.1007/978-3-319-95022-8_192:
The above says essentially what I have been saying for a while now.
4. Does tin/tantulum recovery drive choice of WOF or not
Tin/Tantalum recovery can happen at the DMS circuit stage (around there) and before ball milling, as ball milling grounds the ore to a pulp at P80 of 106 microns. It is where PLS (i.e. see there process flowsheet above) and AVZ intend to recover those credits, but LTR view is Whole of Floatation increases tantulum recovery for them. Probably another reason why they are heading that way.
4. Conclusion
The choice between Whole of Floatation and DMS/floatation becomes one of cost and/or product quality and/or what markets you are intending to target (CG or TG or both CG and TG). IMO Whole of Floatation has lower capex cost (albeit not significantly lower given you still need a number of the capex items before DMS in a process flowsheet) but higher opex costs than DMS/floatation, but choice becomes one of recovery rates and project economics in outcomes and how such costs balance out. It also boils down to what markets you are targeting as well - CG only or a combination of TG/CG.
AVZ has made its choice, others have made theirs.
As a final point,this is Potter report https://hotcopper.com.au/attachments/ltr-23062020-pdf.2255761/?filename=LTR+23062020.pdfsaid the following on the LTR process, noting it doesn't talk about cost of production - the main point it talks about is further reducing deleterious elements is my point,
“Redefining the concentration process to a Whole of OreFlotation (WOF) flowsheet, which reduces the plant’s complexity and risk,increases concentrate grade, and increases the capability to remove deleterious elements from the concentrate.”
Anyway interesting too me choices made for extraction by emerging players, some like MLL/LTR are going for WOF, whilst others like the former KDR/AVZ and some existing producers AJM/Mt Marion are going for DMS/floatation.
All IMO IMO IMO