Ann: Quarterly Activities Report, page-177

We metallurgists work off a recovery to grade curve. If you improve one, you hurt the other. So, if we are targeting a 70% recovery, a 6.0% LiO2 grade would be just out of reach with the current flowsheet. The head grade will not make much of a difference, as all of the presented particles are subject to the same mineral processing steps.

if we are able to supply, say a 5.5% final product, it is easy to increase the dosing rate of the flotation collector reagent, and pull more compound particles (pegmatite with a small piece of spodumene exposed). Likewise with the DMS, it can easily recover 70% of the spodumene, by lowering the circulating media density, allowing more composite particles to report to sinks.

It will boil down to customer specs which way to go. It is also possible to tweak those same variables and create a 6% con for one week and a 5% con, say for the next week.