UPDATE 1.05pm: Shares in MZI Resources firmed after the company announced a 60 per cent upgrade in the resource at its Keysbrook mineral sands project in the State's South West, potentially expanding the project's lifespan.

MZI said the mineral resource at Keysbrook now stood at 78.9 million tonnes at an average grade of 2.5 per cent total heavy mineral.

The company said the additional 29.7 million tonnes readily accessible but would need further negotiation with landholders, local government and regulators to be mined.

MZI said the upgrade could extend the project's minelife from 5.5 years to potentially more than 15 years.

"In MZI's opinion, there is significant potential for further increases in the Keysbrook mineral resource, with the mineralisation envelope defining the mineral resource being open in all directions," the company said in a statement.