Our Lihir operation is located on an island in a volcanic caldera which retains remnant heat within its rock. In the open pit, rock temperatures can reach up to 150 degrees Celsius. The presence of the geothermal conditions presents a unique challenge to our teams to maintain safe and efficient operations.

Lihir’s historic open pit mining practices require our drill and blast personnel to work in conditions where geothermal factors and elevated temperatures pose two potential risks:

• geyser events – where steam and water is ejected from drilled holes; and

• geothermal outbursts – where trapped pockets of steam can vent through the rock.

An innovative program of engineering works, ‘Safe Mining to 150 degrees Celsius’ is underway to enable us to safely mine in areas of higher temperatures.

The program covers each component of the open pit mining system with innovative mechanised and robotic solutions:

• ‘Nil on foot’ aims to keep our operators safe by developing and implementing robotic technology that lets personnel undertake their work from the safety of a vehicle. This requires prototyping and deploying robotic solutions for hole temperature and depth measurement, high explosive assembly loading, emulsion product loading and blasthole geology sampling.

• ‘Nil on bench’ targets the removal of our operators from the pit floor to protect them from geothermal outbursts. Current projects include the deployment of tele-remote technology on dozers, shovels and blasthole drilling rigs.

We continue to work closely with key technology providers to rapidly build Newcrest’s capability to
mine safely at rock temperatures of up to 150 degrees Celsius. This new capability may help offset the extent to which artificial pit cooling is required and may support the continued geothermal power program at Lihir.