GOLD EXTRACTION
Gold without tears
John Chadwick reports on advances in gold recovery,
including cyanide-free and some other innovative
new processes
ining3 (Australia) is leading a
transformational initiative called ‘In
Place’ mining, that involves both
innovative mining and processing techniques.
Mining3 reports that “traditional In Situ
Leaching (ISL) or In Situ Recovery (ISR) is well
known as an established low-cost method for
commodity extraction that does not depend on
rock movement. The ore is processed in situ. It
is used extensively in the uranium sector and for
extraction of water soluble salts (for example
potash) where favourable, generally
sedimentary hosted deposits allow it. The
economics in such instances are attractive. The
circumstances do not depend on energy but
rather metal recovery where the right geology,
geometallurgy and permeability, in particular,
are key parameters.
“However, for ISR, there are of course noted
social/environmental barriers and concerns
relating to conventional acid and cyanide
lixiviants and their potential toxicity issues in
ISL. Likewise, fracking is a concern often
referenced in debates about ISL. Many of these
concerns will be overcome but remain a
challenge in the short to medium term in
applying this more broadly to ore deposits.
“A key enabler for ISR is the development of
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34 International Mining | AUGUST 2017
new lixivian