OZ's total investment to date has been A$22 million.
The South Australian miner is currently sole-funding work on the project, completing a prefeasibility study.
OZ CEO Andrew Cole said the early study results had been encouraging, particularly in the areas of resource extension and metallurgy.
"Our confidence in the project's potential has increased and supports reaching the 51% earn-in level earlier than originally anticipated," he said.
"Recent early metallurgical test work shows significant improvements over the results achieved during the further scoping study with a material improvement in copper and nickel recoveries.
"On results to date, we have also seen an increase in copper concentrate grade while nickel concentrate grade remains in ...