ChucAlookAtthis....It's long reading but I found it very interesting. They keep saying it can't be done but how is this for Technology. True Gold Bugs. How can this be:::::ain't no way <G>. And the non-believers have no problem with the fact that we went to the moon!!!
Excerpt from the Stockman forum. Thanks LeRoy....
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Subject: Gold bug (literally)
Hi LeRoy,
This could be of interest to the forum, though maybe people have
already seen it (just my little contribution):
FEATURE-Gold mining bugs get taste for new metals
By Ben Hirschler
JOHANNESBURG, Feb 12 (Reuter) - For the last 10 years tiny rod-shaped bacteria have been munching their way through gold
ore at South Africa's Fairview Mine, revolutionising gold mining
in the process. Now these genuine gold bugs are to be put to work recovering nickel in Australia and could soon be commercialised for copper production.
The weird Thiobacillus bacteria thrive in an environment lethal to most life forms, deriving their energy from oxidising sulphide ores, thereby liberating minerals which would otherwise be extremely difficult to access.
They have proved a boon to mining companies grappling with refractory gold, which is ``locked'' into minerals such as pyrite, and have achieved gold extraction rates above 95 percent.
Dr Alan Haines of Gencor Ltd (GMFJ.J), the South African mining house which developed the gold bioleaching process, says the technique is attractive both for its low capital costs and
its lack of pollution.
And the same principles which have worked for gold should also apply to other metals trapped in pyritic minerals, such as
nickel and copper.
AVOIDING ACID RAIN
Traditionally, winning metal from these rocks has involved roasting the ore, a process which produces large amounts of
sulphur dioxide -- causing acid rain -- and frequently arsenic.
A modern alternative is pressure oxidation, which is
non-polluting but expensive in terms of upfront costs.
For a small but growing band of mines around the world,
bioleaching refractory ore in specially built reactors has
proved the answer.
Within the Gencor stable, the BIOX process is being used both at Fairview -- where it has solved a major pollution problem -- and at the Sao Bente Mineracao Santa Barbara mine in Brazil.
Outside the group, the technology has been licensed to Wiluna Mines (WNA.AX)in Western Australia and to Ghana's Ashanti Goldfields (AGC.GH), which now boasts the world's largest bacterial oxidation plant.
BIOX is also due to be installed at Minera Lizandro Proano's Tamboraque in Peru later this year and Lonrho (LRHO.L)plans to use it at the Amantaitau Goldfields project in Uzbekistan which it is co-financing.
Trevor Pearton, mining analyst at stockbroker Societe Generale Frankel Pollak, believes there is likely to be a continuing trend towards bacterial leaching in the years ahead.
``There is a tendency to move away from roasting because of the environmental problems as pollution concerns become more and more important,'' he said.
TESTING SAMPLES WORLDWIDE
Over 160 refractory gold samples from around the world have so far been tested for amenability to the BIOX process.
However, the most exciting prospects for bacterial leaching may lie not in gold at all, but in base metals.
Gencor is currently running a demonstration plant to prove the viability of the parallel BioNIC nickel recovery process for
the commercial treatment of the Maggie Hays ore body in Western
Australia, which it jointly owns with Forrestania (FRG.AX).
Production from the Maggie Hays ore body, which is still being assessed, could start around mid-1999.
Haines said Gencor was also getting close to cracking the problem of extracting copper from refractory ore.
Bio-leaching itself is not new to the copper industry, which has for years percolated water containing bacteria through waste
heaps to extract metal.
But so far the high temperatures needed to make the process work rapidly in reactors has confounded scientists.
However, Haines said Gencor had been successfully running a laboratory-scale reactor for a year -- having bred bacteria
which tolerate higher temperatures -- and would shortly build a
larger one which would also be tested for around a year.
The commercial prize could be great. But whereas in the case of gold Gencor opted to license out its technology, for the base
metals it aims to use the technology as a lever to buy into
mining projects.
``We licensed the gold technology but the nickel and the copper we are not prepared to license. The whole emphasis is on
leveraging our way into equity participation,'' said Haines.
For Gencor, setting its sights on a global horizon in the post-apartheid era, bioleaching is a technological key which
could open doors to important growth opportunities. |
