Located in north-eastern South Australia, near Broken Hill, the Portia mine has generated about 320,000 tonnes of ore material since operations started there in April 2015.

CMC, which has mostly completed mining the pit according to its original open pit design, will be paid under a 50:50 revenue sharing agreement with Havilah – the same arrangement as previously.

The company has submitted a revised program for environmental protection and rehabilitation to the South Australian Department of State Development in a bid to reduce delays, having redesigned the mine’s overburden waste dump and tailings storage facility.

Havilah currently has two drilling rigs currently operating at the southern end of the existing open pit, with the aim of further extending the resource.

Drilling at the southern extensions of the pit in August returned 6m at 53.6 grams per tonne, with an average base of tertiary gold mineralisation averaging 12.2gpt over 2m thickness.

Company managing director Chris Giles said the extension would enable the group to continue production for at least another 12 months.

“We are hopeful that our ongoing drilling will outline additional economic gold mineralisation that will allow continued expansion of Portia going forward,” he said.

“Our recent pit floor drilling shows we are also in the fortunate position of having significant amounts of gold bearing saprolite material immediately below the current open pit floor that was not included in the original resource.”

That drilling campaign showed mineralisation more than 20m into the bedrock below the current open pit floor, with the best result being 23m at 6.8gpt gold from the pit floor to 24m below.

Shares in Havilah were down 1.6% or A1c to 61c in early trade, valuing the company at $104.3 million.