REMOVAL of overburden at Havilah Resources Portia Gold Project in South Australia has been expanding with contracting partner Consolidated Mining & Civil (CMC) moving a record amount in July. This has been made possible by steady expansion of CMC’s mining capacity along with high equipment availability.
Removal of overburden by contracting partner CMC is continuing at Havilah Resources’ Portia Gold Project in South Australia, near the border with New South Wales.
Work at Portia began on March 30 and by the end of the June quarter a total of about 1.3 million cubic metres of overburden had been moved. Rates have progressively increased and in July 549,000 cubic metres was removed.
At start-up CMC’s fleet comprised one 250-tonne Hitachi excavator and five 100-tonne dump trucks operating on a 10 day on-five day off roster with one crew. A month later there were two fleets comprising two 250-tonne Hitachi excavators and 10 x 100-tonne dump trucks operating on a 10 day on-five day off roster with two crews.
CMC has acquired a Maptek Sentry monitoring system, which utilizes a long range I-Site scanner and dedicated software that when permanently set up overlooking the open pit, can detect and analyse the smallest of movements in the walls of the pit.
By the end of July there were two mining fleets comprising two 250-tonne Hitachi excavators and 10 x 100-tonne dump trucks operating on a 10 day on-five day off roster with three crews. This allows the equipment to operate at full capacity 12 hours a day and seven days a week. In addition CMC has employed a 120-tonne Hitachi excavator, two Cat 637 scrapers, two Cat D10T dozers and three water trucks plus support equipment.
There are about 50 people in the mine camp with the bus in-bus out transport of personnel from Broken Hill running smoothly and minimizing traffic on local roads.
Havilah has maintained responsibility for dewatering the open pit. Drawdown of saline groundwater is materially greater than indicated by groundwater modelling, with fewer pumps in action. This means that continuously maintaining the groundwater level below the advancing open pit floor level should be achievable, especially with additional pumping capacity being available. The re-injection of this water via the managed aquifer recharge system is functioning according to plan and is accepting all water surplus to operational requirements.
Havilah continues to assemble and refurbish the main components of the gold processing plant. A project manager has been appointed to oversee the task with the view to having the plant on site early in 2016.