Biggest in USA? But worst quality on ASX?, page-11

Don't really want to respond. The known here is that it is a clay with the deposit essentially a lacustrine sediment formation. The Li20 grade is low - at about 0.3% Li20 but still higher than other clays - but is not a brine also, but the key is whether it can be treated viably to produce positive NPV/IRR. Other companies looking at these type of deposits think viability can be shown but the key is around the following:
1. Deleterious amounts in the clays and ease of extraction/separation.
2. Recovery rates.
3. Costs of extraction and amount of reagents to be used.
4. Grain size a key and variability of grain sizes in the resource itself noting it is a lacustrine sediment.

Ultimately it is a new area of development and I'll just leave this paper up for others to form own views - the key to 2 and 3 above is actually 1 and 4, as clay deposits by the very nature they are formed vary between deposits and within the same deposit - a good article IMO on McDermitt itself and some past tests:
Extracting Lithium (911metallurgist.com)

There is a post below yours that suggests attrition scrubbing might work here, so that in itself is interesting given in the above paper that method appears not to have been employed in specimen preparation. But the effectiveness of attrition scrubbing is also based on the shape of the grain size itself, as per below, so it is not as easy as one may think it is.
Attrition Scrubbers (911metallurgist.com)

I also read this announcement/link below and the key for me is how intensive the initial METs were conducted and how that might translate to cost, so will be interesting read with the feasibility studies:
Jindalee Obtains Positive Lithium Metallurgical Results - The Assay

Albeit in terms of the above article I do note there is implication the sediment is not homogenous, which is pretty obvious given how the deposits form, so it will be interesting how they deal with the resource variability issues, how that impacts costs, recovery and viability. This was a key comment in the above article on METs to date - the key words below are "represents portions of the deposit", note the word portions:


Telsa itself which has been floating the idea around lithium extraction in clays, I'll just say at the end of the day did sign an offtake with PLL (a hard rock producer). But it still wants to develop a clay deposit so lets see what technology it develops for a cost effective process there. Obviously technology changes and improves over time so will be interesting how this deposit evolves, but significant METs are required here IMO as that will provide the basis for determining the optimal extraction method and how it translates to cost and recovery and viability, and time will tell. Certainly IMO this evaluation is more down the track but that is IMO.

Will comment no further on this deposit, but will have a look at how they progress over time given the number of players seeking to recover lithium from clays now in this space. Obviously grade is much lower here than hard rocks but ultimately it is a question around recovery and cost, but also meeting product specifications for the battery market, albeit hard rock is better placed for the hydroxide market IMO but time will tell. Low grade brines have been worked as we know to produce battery grade material so time will tell around clays and what they can achieve. I'll leave it at that.

Grade:
Obviously process is different here than hard rock, but in effect you are treating far more resource here where resource grades 0.3% Li20 -compared to hard rock mine where resource grade is much much higher. But to repeat process differs as do costs between the two so it becomes a question about NPV/IRR and risks associated with adopting a new technology to make clay mining viable, compared to established technology for extracting say lithium from brines or hard rock.

Time will tell.

All IMO