Virotec International Ld
10 October 2001
10 October 2001
VIROTEC ANNOUNCES FURTHER SUCCESSFUL TREATMENT
IN BAIA MARE, ROMANIA
Virotec International Ltd ('Virotec'), an environmental remediation company,
is pleased to announce that it has successfully completed its trials on the
treatment of the process water at the Aurul SA* gold mine in Baia Mare,
Romania. The objective of these trials was to reduce the concentrations of
cyanide and copper in the process water to environmentally safe levels in a
more efficient manner before discharge to the tailings dam.
A summary of the results achieved is as follows:
Treatment of decant water
Copper (mg/L) 72.4 3.54
Total cyanide (mg/L) 76.6 3.55
Treatment of liquid separated from the process slurry
Copper (mg/L) 82.7 1.73
Total cyanide (mg/L) 552 3.97
Treatment of process slurry
Copper (mg/L) 82.7 27.5
Total cyanide (mg/L) 552 45.9
Virotec's non-executive director and scientific adviser, Professor McConchie,
'The findings of these trials show that total cyanide concentrations in decant
water and in the liquid phase of process slurries from which the solids have
been separated can be reduced to less than 5 mg/L. Most of the remaining
cyanide is unreactive strong acid dissociable cyanide. However, treatment to
these low concentrations will not be necessary to protect birds and other
animals that may come into contact with water in the tailings dam or to comply
with the new standards for tailings dams specified in the International
Cyanide Management Code developed by the United Nations Environment Programme
and the International Council on Metals and the Environment (September 2001).
The new standards require that the average concentration of free-cyanide plus
weak acid dissociable cyanide be maintained at or below 50 mg/L.
The findings of these trials also show that it is possible to treat the slurry
without separating the liquid from the solids as previously performed on water
treatment projects. We consider this work as a first phase of a programme
designed to optimise the combined reduction of cyanide and soluble metals
deposited into a tailings dam in an active mining situation.'
Virotec has recommended partial separation of the solid and liquid phases so
that the cyanide rich liquid can be reused, thereby reducing overall cyanide
requirements and achieving cost savings. This would reduce the requirement for
water to be discharged from the tailings dam but if a discharge was necessary
then the same treatment procedures can be extended to treat the water to the
necessary discharge standards.
Treatment of Waste Dumps
Trials on the use of the BauxsolTM technology on the remediation of historic
dump sites and decommissioned mine tailings dams in the Baia Mare area have
also commenced and these trials will be monitored over the next 12 months.
Similar trials undertaken at Mt Carrington in Australia have demonstrated the
effectiveness of the BauxsolO technology as a soil enhancement which
neutralises soil, waste rock and tailings acidity. It also binds soluble and
exchangeable aluminium in acid soil profiles which which have been shown to
limit the establishment and continuation of sustainable plant growth. Bauxsol
treated waste rock and tailings from mine sites has proved to be an excellent
plant growth medium for both trees and grasses.
As this phase of the trials have been successfully completed, Virotec will now
focus on expanding its role in this region in Europe.
* Aurul SA is 50% owned by the Romanian Government via a controlled
entity, Remin SA, and 50% owned by Esmeralda Exploration Limited, an
Australian company listed on ASX.
For further information regarding Virotec, go to www.virotec.com .
Virotec International Ltd Tel: 617 5530 8014
Melissa Toomey, SPIN Business Solutions Tel: 617 3251 8111
David Youngman, W. H. Ireland Ltd Tel: 0161 832 6644
Shane Dolan/ James Benjamin, Biddicks Tel: 020 7448 1000