Ann: 2022 Annual Report, page-22

The other bit nobody seems to have mentioned is that they say not only do they expect the Lithium price to remain strong but they also expect the global deficit for lithium to widen which indicates prices may well keep increasing.
Also worth noting that if they just keep the surplus cash on the balance sheet for the next two years and wait for the franking credits to build up they may well earn around $200M - $250M just in interest over the two years.

"Pricing for FY2023 is expected to remain strong, with growing evidence that the global lithium deficit will continue to widen as demand outstrips supply.
A recent report published by the International Energy Agency (IEA) concluded that global battery and minerals supply chains need to expand tenfold to meet projected critical minerals needs by 2030".
The IEA expects demand for EV batteries to increase from around 340 Gigawatt hours (GWh) today to over 3,500 GWh by 2030, with the industry projected to need 50 more lithium mines by 2030 to meet global net carbon emissions goals.