These 100Mt comments are an urban myth spread typically by those...

These 100Mt comments are an urban myth spread typically by those invested in large deposits that are close to or above this size threshold. IMO it is not founded on any financial facts, but thank you for continuing to spread this myth. Presumably you have made investments in lithium companies closer to or within this larger size category and it makes you feel better about your investment decisions despite collapsing share prices for those investments (both large and small companies are being hit by softer lithium prices).

Evaluating this 100Mt myth from a revenue viewpoint
1Mt of say 1.3% material concentrated to SC6 with a 70% recovery rate is 152kt of SC6. If a company were, over time, to process 100Mt they would have 15.2Mt of SC6 which at even US$1,000/t would be US$15.2b in revenue. Its clearly nonsense to suggest that to be commercial a lithium operation must expect to generate US$15b in revenue over its life of mine. That doesn't stop these suggestions.

Time value of money viewpoint
If you had a 1Mtpa concentrator and had 100Mt of resource that was able to be mined, the deposit would last 100 years. Clearly you do not need to have a 100 year mine life to be economic. Trying to go with a startup life of mine under 10 years can be problematic but once you are into the 10 to 15+ year period (with exploration potential to expand that), life of mine is no longer the primary driving factor around economics. The table below is the present value of $100 at different time periods with an 8% discount rate. Those periods beyond 15-20 years are very heavily discounted in NPV calculations. Having a life of mine beyond this is not necessary to get the commercials to work. What typically happens is the ore that would be processed beyond years 20-25 is brought forward by expanding the size of the proposed plant. For example 1Mtpa over 40 years becomes 2Mtpa over 20 years. The exception being integrated projects involving Hydroxide as these target a >20yr minimum life of mine after completion of the Hydroxide plant and at least two (Mt Holland and Jadar in Siberia) have targeted 50 years.



Where is the commercial threshold?
What is necessary is generating enough margin quickly enough so that the capital cost can recovered with a sensible payback which will allow the project to be NPV positive. Isolated deposits below ~5Mt will pretty much always struggle with this in anything but very high prices. If the capex build it more expensive as it frequently will be, ~10-15Mt of resource may be the minimum that can be commercial. Higher grades can make lower volumes work. If open pit, it becomes a complex array of grades, strip ratios, mining costs, recovery rates, processing costs, distance to port, royalty rates and any other factors that impact economics. Multiple projects smaller than 20Mt at FID have produced scoping studies with good financial economics and several have made it into production.

Economic resource vs defined resource
One of the features of many Australian lithium companies is that within their JORC they have identified lithium resources that are expensive to extract but including this material in the JORC has added to the reported JORC scale. When economics are wrapped around the deposit, a lot remains in the ground. For example LTR started with a 156Mt resource but its proven and probable resource was 68.5Mt. Nearly 90Mt had attributes that for one reason or another mean the ore wasn't drilled to measured and indicated and didn't make it into the mine plan at FID. When companies drill with this approach, you do need a lot larger resource to get the ore reserve economics to work.

Smaller focused deposits are less likely to have this effect. 40Mt that is all able to be efficiently mined may have equivalent financials (at low revenue price points) to an 80Mt deposit with lots of deeper seams and an open pit mining plan.

ASIC of $700
I presume you are referencing USD and this is indeed a sensible benchmark. In the current market you ideally don't want to have a project that is much above this price point (>A$1000/t). Projects with higher price points have more risks as they will be further to the right on the cost curve and will need prices to increase to commence and during periods of low prices may lose money.

TG6 has not supplied any ASIC/C1 cost estimates so its unclear where you form the opinion that TG6 has a cost structure that doesn't work. I can only presume this comes from confusing ASIC and pit envelopes. They are not the same thing and multiple examples exist where huge gaps exist between the size of the project ASIC and the pit envelope used. For example LRS used a US$1,500/t pit envelope within its June 2023 JORC - the last one before its PEA (ref page 9/21 of 20 June 2023). When LRS produced its PEA in Sep 2023 that referenced a strong AISC of US$536/t. There are some interesting attributes to that project but it shows the pit envelope of US$1,500/t that TG6 is using doesn't mean its on-track to be uneconomic.

For clarity, LRS has lowered its pit envelope in its May JORC update to US$1,200/t.