TORONTO (miningweekly.com) – Canadian project developer Platinum Group Metals (PTM) has increased the resource estimate for platinum, palladium and gold (3E) at its 58.62%-owned Waterberg Joint Venture (JV) project, expanding the inferred resource and improving the confidence in previous results.

The Vancouver-based company on Tuesday reported that effective July 20, the mineral resources at Waterberg on a 100% project basis had risen to an estimated 25.64-million ounces of 3E in the inferred category, in addition to 12.61-million ounces of 3E in the indicated category.

The inferred resource comprised 246-million tonnes grading 3.25 g/t 3E (0.98 g/t platinum, 2.11 g/t palladium, 0.16 g/t gold at a 2.5 g/t cutoff). The indicated resource comprised 121-million tonnes grading 3.24 g/t 3E (0.97 g/t platinum, 2.11 g/t palladium and 0.16 g/t gold).

Meanwhile, ten drill rigs were currently active at the Waterberg project, which was located in the northern limb of South Africa’s Bushveld Igneous Complex. The deposit remained open for expansion. JV partner Japan Oil, Gas and Metals National Corporation (Jogmec) was funding drilling and engineering work under a $20-million firm commitment to the JV.

PTM reported that the shallowest T-zone intersection was at 140 m below surface. The current drill programme was designed to expand the shallow T-zone resource for prefeasibility planning. Super F-zones within the resource, where thickness exceeded 15 m, were also a focus of current drilling.

The thicker zones had the potential to add significantly to early mine plans for bulk mining methods being considered in the ongoing prefeasibility study (PFS).

The PFS was being completed by project teams from global independent mining engineering firm DRA, along with PTM on behalf of the Waterberg JV. Metallurgical work, plant designs, metal marketing studies, costing, engineering, servitude layouts for water and power and project planning were advancing as drilling continued for further resource expansion and definition.

On May 26, the company announced that Jogmec, PTM and empowerment partner Mnombo Wethu Consultants had agreed to consolidate the Waterberg JV and the Waterberg Extension projects into one project area. The Waterberg JV prospecting rights covered about 780 km² with a further 331 km² in accepted applications.

Prefeasibility work on the overall project was progressing, with budget quotations currently in progress for the delivery of bulk services of electricity and water and upgraded roads.

Metallurgical results completed by DRA had generally confirmed earlier work completed as a component of an earlier preliminary economic assessment at Waterberg. Samples were analysed with grinding and flotation tests and had provided about 80% recovery with a 100 g/t concentrate on the F-zone.

Further optimisation and flow sheet design work was also proceeding.

PTM reported that the Waterberg material showed an “encouraging flotation response", producing a saleable clean concentrate final product.