Poised to become a mid-tier gold producer

Burnstone Mine commenced production build up in Q1 2011. As such, all components of the mine required to enter commercial production have been commissioned and completed, and the development phase has concluded. Major capital projects included the vertical shaft, metallurgical plant, decline, ventilation shaft and required surface and underground infrastructure.

Vertical shaft complex

The vertical shaft is intended primarily for rock hoisting, but is also equipped for the insertion and extraction of men and material. For this purpose, two winders have been installed. The 7.5 meter diameter vertical shaft, lined with 300mm concrete is designed for the extraction of rock at a rate of 206,000 tonnes per month. The shaft bottom lies at 1,601 ft or 488 meters. The decline was also holed with the vertical shaft, resulting in additional access to 40 level as well as improved ventilation. The development of the remaining underground station infrastructure that includes another three ore passes, the settlers and a clear water dam commenced in November 2010 and will be completed in 2011 which will allow the vertical shaft to operate at full design capacity.

Metallurgical plant

Burnstone’s metallurgical plant was designed for a production rate of 125,000 tonnes per month with an increase to 175,000 tonnes per month by adding a second ball mill in-line with the production profile of the mine. A combination of a Semi Autogenous Grinding (“SAG”) mill and Ball mill with a Carbon-in-Leach (“CIL”) process is used to maximize recoveries.

An aggressive construction schedule was followed to ensure the plant, on which construction commenced in February 2010, was delivered as a fully integrated, commissioned unit by the end of the same year. Despite encountering various challenges that included extraordinary rainfall, extreme cold winter as well as the impact on deliveries and contractors by the FIFA World Cup hosted in South Africa in July 2010, the plant was delivered on schedule.

The crusher and the silo feed conveyer were also commissioned in October, 2010 and conveyers were run at low speed for the duration of the commissioning phase to ensure optimal performance prior to production. The tailings storage facility, inclusive of a bulk water storage dam was completed to coincide with the commissioning schedule of the plant.

Gold slag recovered from the mills during the refurbishment process was used to commission the gold room in October, 2010. Burnstone’s first gold pour took place on October 31, 2010 with gold recovered through the gravity circuit. Commissioning of the gravity and CIL circuits as well as the thickener was also completed allowing for the uninterrupted processing of material.

The plant achieved its targeted rate for January 2011 of 90,000 tonnes milled. The current focus is to ramp up production and achieve a milling rate of 125,000 tons per month by Q3 2011.

Power

The first phase for power supply to Burnstone consisting of 21 MvA, and on-site power reticulation has been completed and all on-site facilities are connected to Eskom power. Power supply to site will build-up to the required 51 MvA with the upgrade of the existing Eskom sub-station and feeder lines by the end of Q3 2011. Current Eskom supply is adequate for the planned production build-up, and diesel powered generators which were used for power generation during the construction phase, will remain on site as future back-up.

Ventilation shaft

The raise boring, or holing, that comprised phase one of the ventilation shaft project took place in May 2010 and included the piloting and reaming of a 5.1-meter diameter, 305-meter deep vertical ventilation shaft, which will act as an up-cast shaft to provide sufficient ventilation for mining of blocks B and C, targeted over the next three years. Phase two, which has also been completed, consisted of establishing support by lining the first 90 meters of the shaft with shotcrete as well as connecting three 720 kW surface fans. The shaft will provide necessary ventilation for the underground workings well into the future.