Ann: Global Consortium Backs Australian Energy Security, page-15

Benchmark Intelligence estimates that Tesla will require about 25,000 tonnes per year of lithium (6% of global supply), 112,500 tonnes per year of flake graphite, 45,000 tonnes per year of spherical graphite (28% of global supply) and 7000 tonnes of cobalt per year (7% of global supply) if it reaches its target capacity of 35 GWh by 2020.

https://finfeed.com/features/tesla-model-3-splashes-make-waves-graphite-lithium/20160406/

If you divide those figures to get to 15GWh you end up with the following:

Flake graphite - 48,913 Tonnes
Spherical graphite - 19,565 Tonnes

Total flake (before any spheronising at 70% yield)
48,913 + 25,434 (19,565 spheronised) = 74,347 Tonnes

That is of course assuming Benchmark's figures are correct or close.

If benchmark meant use the flake graphite to create the spherical we would still need 19.5K Tonnes of spherical (25K+ Tonnes flake at 70% yield) for the 15GWh factory.

I think what everyone needs to understand is that it is not just about mining xxx Ktpa anymore.

Magnis is looking to build and part own a Gigafactory in Australia making and selling battery cells with the IP it holds.