In August 2012 BHP Billiton announced its intention to investigate an alternative, less capital-intensive design of the Olympic Dam expansion, involving new technologies, to substantially improve the economics of the project. A number of new mining and processing technologies are being evaluated to determine the best development path.
Laboratory and pilot scale trials of heap leaching as an alternative process for extracting metals from ore mined underground have shown promising results to date. In order to further test this processing method at a larger and more integrated scale, BHP Billiton has lodged an application for assessment by the Australian and South Australian Governments to construct and operate a demonstration plant on the existing mining lease at Olympic Dam. Should approval be granted, and subject to BHP Billiton approvals, construction of the demonstration plant is expected to commence in the second half of calendar year 2015 at Olympic Dam with a projected trial period of 36 months which is expected to commence in late 2016.
Record mining rates at Olympic Dam underpinned an 11 per cent increase in copper production in the 2014 financial year to 184 kt. While an annualised production rate of 219 kt in the June 2014 quarter indicates the degree of improvement achieved in the existing underground operation, volumes in the 2015 financial year are expected to remain broadly unchanged as a result of the current smelter maintenance program which is expected to be completed early in the September 2014 quarter. A major smelter maintenance campaign is scheduled to commence in the June 2015 quarter.