You're not paying attention, or you don;t care me thinks. Clay hosted deposits are all relatively large tonnage, low grade and economics really boils down to leach costs vs modest revenue per tonne potential at best. Acidity (pH) and acid consumption to get and stay at that pH of the leach solution determines variable opex beyond almost fixed dig, pad, leach, strip, tails management, rehab etc, etc clay deposits require.
So OD6 released their first ANSTO met work recoveries recently in this release.
https://hotcopper.com.au/posts/67095679/singlepH is only mentioned once in the report... referring to pH of local saline lakes
Why is that you think
Below is the range of leach solution acidity used for test results (in an obviously non-commercial 2 w/v% slurry). No mention of acid consumption to achieve and maintain "Free Acidity" at these levels...
25g/L free HCl has a molarity of 0.815 which has a pH = 0.09 (basically 0, which is 10 times stronger than pH=1, which is already 5000 times more acidic than pH=4.5)
100g/L free HCl has a molarity of 3.26 which has a pH = -0.5 (150 times stronger than pH=1, which is already 5000 times more acidic than pH=4.5)
Keep the 100g/L HCl in the fume hood and rubber gloves on when handling
No wonder in doing their 'victory lap' the MD said results were achieved with "simple" and not low HCl strength, and he was looking forward to potentially lowering acid strengths
Almost nobody has any idea what is actually going on with clay hosted deposits, companies usually release almost impossible to calculate data regards the critical variables (or just not at all) and spin the story around the EV-RE-China thematic gift that keepers on giving for grifters. Maybe OD6 nails the met recovery with sensible leach solutions, but I guarantee they won't confess if they can't...
(20min delay)