Market Survey on Copper - Indian Bureau of Mines

One of the first of the recent series of major investments was an in-pit, semimobile
gyratory crushing unit linked to the Copperton Concentrator by an 8km
conveyor system. This reduced haulage distances from the working faces substantially
but even so the mine needs a large fleet of Caterpillar mechanical drive and Komatsu
electric-drive trucks, mostly of 218t-capacity, to service ten P&H electric rope
shovels.
Dispatching is by the Modular Mining computerised system and Bingham also
utilises Thunderbird Pacific's drill monitoring and logging systems. Both GPS and
Glonass are used for precise drill positioning. Germany's MAN Takraf has upgraded
and relocated the semi-mobile in-pit crushing plant and conveyor system to keep
trucking distances down.
Processing
The Copperton concentrator was expanded in 1992 and fitted with some of the
world’s largest SAG and ball mills, and large flotation cells. There are four grinding
and flotation lines, sequentially yielding a copper and molybdenum concentrate. The
copper concentrate is piped about 27km to the smelter. Until its closure in mid-2001,
the older North plant supplied about 20% of the copper concentrate for smelting. Rio
produces approximately 8% of the world's molybdenum.
The current smelting facilities are the result of major investment, comprising a
new primary flash smelter and flash converter system, designed by Outokumpu with
input from Kennecott, plus a slag treatment plant. The converter treats matte that has
been granulated and powdered. The 98.6% copper from the new converter is refined
to 99.5% copper in two anode furnaces.
Cast anodes are railed about 3km to the refinery’s electrolytic tankhouse, where
marketable high-purity copper is produced and the gold and silver content of the
concentrate is also recovered.
Production
Having been regarded as a minor contributor to income at Bingham Canyon,
increased world demand for molybdenum has now made it very important. Income
from moly sales was just $30m in 2002, but rose to $700m in 2005. The 2008 mine
plan was modified to include areas of higher moly content, even at the expense of
copper, while the concentrator has also been fine-tuned to optimise moly recoveries,
with a second expansion of the moly-recovery circuit commissioned in mid-2006.
Rio produces approximately 8% of the world's molybdenum and expects to
produce 60 million pounds by 2015. In order to improve efficiency, it is constructing
an autoclave process in Magna to produce molybdenum instead of outsourcing. The
plant is estimated to cost $340m and is scheduled to be completed by 2012.
Operations are expected to begin in 2013.
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