Perth-based Pioneer Resources has started mining its Sinclair operation in Australia, bringing online the country’s first commercial caesium mine.

Extraction of overburden from the upper reaches of the Sinclair stage one pit is underway, which will provide access to the caesium mineral pollucite, located some 40 m below surface.

While the company’s primary focus for Sinclair, part of the wider Pioneer Dome project, is the extraction of pollucite, it is also expected to yield a number of other minerals including potassium feldspar (much of which is included in the overburden being mined), lithium and silica.

The Sinclair mine is not only a rarity in Australia; it is also one of only three commercial caesium producers in the world, according to Pioneer.

Managing Director David Crook said the commencement of operations at Sinclair, two years after the discovery hole was drilled, was a major milestone for the company.

“We look forward to an efficient and safe mining operation, which, while modest in size, should provide funds for drilling and further discoveries at the Pioneer Dome and other company projects,” he said.

Pioneer said its mining contractor, Hampton Transport Services, recently completed mobilisation to site as well as preliminary site works, which were pre-cursors to the commencement of full-scale mining.

Pioneer’s stage one plan for Sinclair would see the company carry out four months of mining activity, with the pollucite sold to Cabot Corp as part of an offtake arrangement. Potassium feldspar and lithium minerals would be stockpiled and marketed as part of this.

Stage two, expected to commence in 2019, would see six months of mining activity and a cutback to expose a large potassium feldspar and remaining lithium mineral resource.

The company is currently in the process of finalising a maiden potassium feldspar resource estimate for Sinclair, it said.