This follows early termination of the contract at Antas for AVB Mineracao Ltda, a subsidiary of Oz Minerals.
The contract was due to conclude in 2020 and the reduction in the Work in Hand (WIH) position as a result of the early termination will be circa $8 million.
It is expected there will be a non cash impairment related to the cessation of operations in Brazil of approximately $2 million.
In addition, there are unrealised forex losses that will be triggered upon closure of the subsidiary, of approximately $5 million based on current exchange rates.
Shares in MACA (ASX:MLD) are trading 0.5 per cent higher at 98 cents.