Ann: Southdown Magnetite Project Prefeasibility Study, page-93

https://www.bigmint.co/insights/detail/how-will-global-iron-ore-market-be-impacted-after-simandou-enters-production-bigmint-explores-561947
It should be noted that Macquarie expects the iron ore price to drop $40/t over the next few years as a result of Simandou and other mines coming online.
GRR has not generated any positive operating cashflow in the first six months of this year but previously predicted $125mil in positive cashflow this calendar year to finance the development of the North Pit underground project and also projected that most of the funds to finance this development would come from positive cashflow from the open pits between 2024 to 2029 - that was always an inherently weak proposition and simply won't work - if they decide to go ahead with this development later this year then you should expect the penny would have dropped on their proposed financing method and will be replaced by a massive equity issue with the potential to double the number of shares on issue. And the only reason why they would go ahead would be to supply the mothership with cheap product.
Hopefully the above link works as shareholders should be reading up on Simandou to gain a proper understanding on the near-future iron ore market.