Millennium Minerals has reached a milestone at the Nullagine gold project by producing its first gold from the site’s stage one sulphide plant expansion.
The company embarked on a low-cost, two-stage expansion of the Pilbara, Western Australia-based site’s existing Golden Eagle carbon-in-leach (CIL) plant four years ago.
It secured $17.5 million in funding from Investec Australia last year to help fund the project. Commissioning of stage one commenced in April 2019, with stage two to follow in early 2020.
The expansion is taking advantage of high-grade sulphide deposits not previously accessible, helping maintain its average annualised production rate above 100,000 ounces of gold, while extending the mine life from three years to more than five.
Millennium’s early analysis indicates the expanded sulphide circuit has performed “in line with or exceeding” expectations since commissioning of the ultra-fine grind mills between June 19–24.
The company will next install in-mill oxidation (INOX) and pressurised in-mill oxidation (PINOX) facilities for processing of blended pyrite and arsenopyrite-dominant ores.
Millennium chief executive Peter Cash said the early results from the sulphide circuit were positive, with the potential to cost-effectively process Nullagine’s high-grade sulphide ore source a “core component” of the company’s growth plan.
Roughly half of Millennium’s ore feed is expected to come from these sulphide sources in the remainder of 2019, the company reported.
“The past 14 months have been a very capital-intensive period for the company, where we have made significant investment in long-term growth initiatives including the sulphide plant expansion and the development of sulphide ore sources,” Cash said.
“This has had an impact on production and cash flow over the past six months, however we are now moving into a period where we expect to see both production and cash flow increase strongly, with an expected return to positive cash flow by the end of July.”
In addition to Millennium’s plant expansion, the company announced plans earlier this year to develop a $10 million second underground mine at the project.