BHP Billiton Plans Large-scale Heap-leach Test at Olympic Dam
BHP Billiton reported in late July that laboratory and pilot-scale trials of heap leaching as an alternative process for extracting
metals from ore mined at its Olympic Dam
copper-uranium mine in South Australia
have shown promising results. To further
test heap leaching at a larger and more
integrated scale, the company has lodged
an application for assessment by the
Australian federal and South Australian
governments to construct and operate a
demonstration plant on the existing mining
lease at Olympic Dam.
If BHP Billiton receives the required
approvals, and also subject to internal
company approvals, construction of the
demonstration plant could begin in the
second half of 2015, followed by a projected trial period of 36 months beginning
in late 2016.
Prior to September 2012, BHP Billiton
spent several years investigating a huge
expansion project for Olympic Dam.
Project design included a new open-pit
mine that would have eventually consumed
the existing underground mine. Production
would have increased from 180,000 metric tons per year (mt/y) to 750,000 mt/y of
refined copper, plus associated uranium
oxide, gold and silver. The existing smelter
would have been expanded, and new concentrator and hydrometallurgical plants
would have been constructed, along with
new waste rock and tailings storage facilities and major infrastructure projects.
Capital costs to develop the expansion
were estimated at about $30 billion.
In September 2012, BHP Billiton
announced that it was abandoning the
high-cost plan and would investigate alternative, less capital-intensive designs. The
company’s current plan for a heap-leach
demonstration plant is a result of those
investigations.
In BHP Billion’s fiscal year ended June
30, Olympic Dam produced 184,400 mt
of copper cathode, 121,300 oz of gold,
and 4,000 mt of uranium (payable metal
in concentrate).
As featured in Womp 2014 Vol 09 - www.womp-int.com