Taseko Mines says it has reached “commercial grade levels” at its Florence in-situ copper test mine in Arizona, USA, less than six months after well field operations commenced.

The company cannot yet say it is a ‘commercial mine’, but it is well on the way to being able to with permits amendment applications to transfer the test facility into a commercial operation being delivered and financing arrangements being made.

On the former, Taseko said the Aquifer Protection Permit (APP) amendment application for Florence was now on its way to the Arizona Department of Environmental Quality (ADEQ). “The APP is one of two key permit amendments which are required for commercial production at the company’s Florence copper project,” Taseko said, adding that the permit amendment application for the Underground Injection Control Permit will be made to the US Environmental Protection Agency in the coming weeks.

Russell Hallbauer, Chief Executive Officer of Taseko, provided the update on operations at Florence. “This past week, after roughly six months of operating the test facility, the leach solution reached commercial grade levels, well in advance of our anticipated timeframe,” he said.

“Based on previous bench-scale testing, we expected it would take upwards of a year to reach target solution grade, so we are obviously extremely pleased to have achieved this milestone after such a short period of time.”

Hallbauer said the grade of the leach solution coming from Florence’s main recovery well is around 1,600 parts per million (ppm) of copper in solution and would be comparable to a typical open pit, low cost heap leach operation.

“The main difference between Florence Copper and other leach operations is that we have no mining costs associated with our in-situ leach process, making Florence Copper, when in commercial operation, one of the lowest cost operations globally,” he said.

The main focus of the Florence test facility, beyond ensuring the company achieves all the technical targets of its feasibility study, will be building the company’s on-the-ground operational experience to streamline the transition to commercial production, according to Halllbauer.

“Based on the knowledge we have gained in the last six months, the benefits of the two phase approach (production test facility followed by the commercial facility) will significantly improve the ramp up of the final commercial scale operation,” he said.

Stuart McDonald, President of Taseko, said financing for the commercial production facility is progressing with multiple options continuing to be pursued.

“We have initiated discussions with potential lenders and financing partners and we remain on track to have a plan formalised in the coming months,” he said.

“We now have the three key initiatives – technical, permitting and financing – all aligned for our project to be construction-ready in the first half of 2020.”

The commercial Florence mine is expected to produce copper at average operating costs of $1.10/Ib ($2,425/t), come with a capital cost intensity of $5,200/t of copper capacity and yield a pre-tax net present value of $920 million. It also has a slated copper production capacity of 85 MIb/y (38,555 t/y) and a 21-year mine life.