New Zealand's
largest gold producers' OceanaGold Macraes Mine is characterised by a large
tonnage and relatively low grade operation. To survive in diminishing real gold
prices, the operation must focus on a culture of continuous improvement. This
paper presents the outcome of a supplier sponsored continuous improvement
project known as the Orica Advanced Mining Services project.

In
March 2004 OceanaGold (then GRD Macraes) entered into an Advanced Mining
Services (AMS) project with Orica Mining Services. The motivating factor behind
OceanaGold's need to improve bulk waste productivity and SAG mill throughput was
the planned increase in production from five million to 5.4 million tonnes per
annum. A stripping ratio of ten to one meant that optimisation of the drill,
blast and production functions was paramount.

The
primary focus of the project was to optimise the drill and blast parameters to
suit the variable rock conditions throughout the mines main operating pit
(Frasers Pit). Fragmentation of the ore for presentation at the SAG mill, and
cost reduction on the mining of bulk waste movement, were the primary
objectives. A number of additional initiatives complimenting the interface
between drill, blast and ore production were also established. These
included;

reduced ore loss through delineation of ore boundaries to
allow for blast movement;

established blasting parameters for variable geological
conditions, resulting in improved fragmentation; and

improved asset utilisation by establishing a blasting
regime that angled grade control holes to be used as blastholes in the
stockworks area.

A
year into the project, the philosophy of continuous improvement is now
in-grained at the Macraes minesite. As the project continues, the focus is on
the further refining of those procedures established, to ensure a continued
focus on lower unit mining production costs.