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.