Train 1 ponds are 100 + 25 Ha, used to drain the supersaturated...

Train 1 ponds are 100 + 25 Ha, used to drain the supersaturated Williamson pit.
DFS states total ponds required = 686 + 96 Ha.
The supersaturated pit has yielded 27Kt salts which should produce 2.9Kt SOP (as per DFS, salts harvested 2.27Mtpa to produce 245Ktpa with the addition of 42Ktpa MOP)?
They drained the pit in H2 2019? Evaporation cycle has taken over 12 months??
I’m prepared to have my maths corrected but I’m scratching my head working out how they are going to produce 245Ktpa. I could be misunderstanding something?
Is the halite included in the 2.27Mtpa??