Patience: do it once & do it right, page-154

Lets say bauxite prices rise only 6/t
at 24/t margin x modest upscale to 2 mt pa. not difficult math and not out if the question. There's your 48m pa.
When you consider that they do state a 4-5 mt pa may be on the cards.

But let's just focus on 800kt pa start up first will do to get the re-rate on its way.