ST BARBARA’S Simberi mine moved record volumes of ore and waste in the March quarter, aided by new mining equipment that commenced operating from mid-February, the company said.
During the quarter, a new mining pit ‘Pigibo’ was brought into production, which required waste stripping, new roads and earthworks.
St Barbara said the initial surface Pigibo material is much lower in density than the other pits currently in use, however, it requires about 40 per cent more material in volume to be moved to achieve similar tonnages.
Simberi experienced a two week stoppage in the aerial rope conveyor as a result of a failed splice in the conveyor belt.
St Barbara said impact on production was lessened by bringing forward planned waste stripping activities and increasing ore haulage by truck.
Sections of the conveyor belt have been identified and planned for future replacement, the company said.
At Simberi, all in sustaining cost for the March quarter was A$1,404 per ounce with the increase on the previous quarter a result of lower production volume and impacted by recent expenditure on a mining fleet.
Simberi gold production was 25,433 ounces for the quarter and 110,488 ounces for the 12 months to 31 March.
This exceeds the targeted 100,000 ounces per annum run rate for the fourth consecutive quarter and for the rolling 12 months, the company said.
The pre-feasibility study (PFS) for the Simberi sulphide project was completed in April and confirmed that the project could extend mine life at Simberi by a further eight years.
The PFS was scoped to focus on low capital expenditure solutions that utilise existing infrastructure on Simberi Island, including the airport, power station, village and wharf, St Barbara said.
In addition, the existing semi-autogenous grinding (SAG) mill and scrubber-ball mill would be used in a new plant flowsheet, maintaining the ability to process both oxide and sulphide ores.
St Barbara said the PFS indicated the production and sale of a concentrate is the preferred option, as it avoids the need to establish downstream processing on the island.
Moving forward, to finalise the study an independent review of the resources estimated used to inform the PFS will need to be completed.
Results of the resource estimation will be released in August this year.
To avoid an interruption to production, the company said a decision on the sulphide project is required by March 2017.
Trenching at Bekou South on the Simberi mine lease was completed during the quarter, targeting oxide mineralistion and additional trench sampling at Banesa Au-Cu porphyry prospect on Big Tabar Island was also completed during the quarter.
St Barbara also said mapping and surface sampling commenced at Fotombar prospect on Big Tabar Island during the March quarter.
St Barbara’s 2016 financial year forecast for Simberi gold production is maintained at between 100,000 and 110,000 ounces at an all in sustaining cost of between A$1,350 and A$1,430 per ounce, with capital expenditure of between A$10 million and A$12 million.