On the subject of royalties, some details below on Wonmunna.
https://www.nsenergybusiness.com/projects/wonmunna-iron-ore-project/
Given reserves are 28mt and resource is 80mt with 10mt already mined (at rate of 5mtpa), then there is probably around 10 year mine life. Did some calculations and the NPV probably works out to be $50m at IO price of 90 USD/t (150 AUD)
Noticed TLM also spends more on exploration than RHI although RHI has less prospective ground.