PERTH (miningweekly.com) – A prefeasibility study (PFS) into the Nyanzaga gold project, in Tanzania, shows the project can deliver an estimated 213 000 oz/y of gold over a 12-year mine life.
ASX-listed OreCorp on Monday reported that a capital investment of some $287-million would be required to develop the project, with the PFS determining that a concurrent openpit and underground mine schedule represented the optimum mining sequence for the project.
A further $50-million in capital spend would be required to fund the development of the underground operation, which is likely to be funded out of the operating cash flow from the openpit mine.
The openpit operation is expected to deliver some 1.75-million ounces of contained gold over the life of the project, which is 25% higher than estimated in the previously completed scoping study for the pit.
Underground mining, which would start in the first year of operation, is expected to produce some 1.16-million ounces of contained gold, with the underground operation to be developed to a depth of 800 m below surface, while the deposit remains open at depth.
The PFS estimated an all-in sustaining cost of around $838/oz.
OreCorp told shareholders on Monday that there was potential to further enhance the project economics by conducting a detailed geotechnical drilling programme to further optimise pit wall angles, potentially reducing the openpit stripping ratio, and to optimise the openpit and underground mine designs.
Work can also be done to develop first principal cost models for both of the mining operations to fully investigate the operating and capital cost trade-offs between contract mining and owner-operator, while a mine to mill optimisation study to examine plant throughput and gold production during the early years of operation, can also be undertaken.
OreCorp said the positive results of the PFS underpinned the company’s strategy of focusing on near-term production and generating an early cash flow, and further demonstrated the potential of Nyanzaga to deliver significant returns for shareholders from a gold operation with competitive costs.
OreCorp will immediately start work on a definitive feasibility study on the conclusion of a definition of the scope of the study with its joint venture partner Acacia.