16 March 2001

 TUCF Train Seven Local Divers for PT. Newmont Nusa Tenggara (PTNNT)

A landmark, five week intensive, diver training program saw seven local divers complete the equivalent of an ADAS Part 2 Restricted diver course, on the Indonesian Island of Sumbawa.

The Underwater Centre Fremantle was awarded the contract, (over tenders from Australian and international commercial diving schools), to train the divers who will work on various subsurface maintenance tasks on the Batu Hijau project. In addition to training, the PTNNT divers needed to be equipped with the latest commercial diving gear. This was supplied by Pacific Commercial Diving Supplies - Perth (PCDS).

Batu Hijau is a large copper/gold porphyry deposit containing reserves of 11.8 million ounces of gold and 10.5 billion pounds of copper. Batu Hijau is on the southwest corner of the sparsely populated island of Sumbawa, 950 miles east of Jakarta. PTNNT constructed a deep water port at Benete Bay, a power station, townsite, processing plant and mine from green jungle just three years ago. Batu Hijau employs approximately 5,000 people. Sixty percent of the employees are from the province where the mine is located.

Batu Hijau is an open pit mining operation. Hydraulic shovels load the ore onto haul trucks for delivery to a primary crusher. The crushed ore is then transported to a concentrator via conveyor. At the concentrator, the ore is wet-ground in a slurry to the consistency of fine sand in a series of semi-autogenous (SAG) mills and ball mills. The ore-bearing slurry is then injected into large flotation tanks of seawater mixed with detergent-like chemicals. Air, bubbling through the water, causes grains of gold and copper to "float," while barren minerals sink to the bottom of the tank. The concentrated ore is skimmed off the surface, collected, thickened and sent by pipeline to Benete Bay, where the ore is dried to a consistency of wet sand and stockpiled for shipment to smelters around the world.

The Batu Hijau project will utilize subsea disposal of tails. The barren minerals are removed from the tanks and deposited via pipeline on the deep sea floor. Because they are completely natural and are protected by the seawater from atmospheric oxygen, they pose no threat to the marine environment.

Given the reliance on sea water to support so many aspects of the mining operation, large intakes and pumping stations have been constructed to supply the necessary water. It is these intakes and pumps where the newly qualified divers will spend most of their time working. Indeed, during the course, the TUCF training team was called upon to assist with the maintenance of one of the sea water pumps at Teluk Senunu. The PTNNT divers will also be assigned diving tasks in and around the port at Benete Bay.