March 2011.Cyanide Removal from the Rosia Montana Mine, Transylvania, Romania.Another ‘red river’ project; Cornwall, Spain, Romania,—-
The new mine that is planned by the Rosia Montana Gold Corporation (80% Gabriel Mining of Canada and 20% Romanian State Mining Company who at present operate a small traditional mine on the site).
The location of the mine is in the Rosia Montana valley in the Apuseni Mountains, part of the Carpathian chain. The area is a well known metalliferous mining area and metals such as Gold, Silver, Copper, Zinc and Arsenic have been won by mining for millennia.
The plan is to create a large opencaste mine, amongst the largest in Europe that will access the rock from which large reserves of Gold are present. This operation has been through a protracted (over 10 years) scoping and planning regium that has culminated in receiving the State’s permission to mine in the summer of 2010. The only requirements that are holding up operational start up are environmental licences. Most of these licences are regarding the environmental issues of contaminated water from the site. These include surface water management and the fate of process water used in the shedding of the gold and other metals from the base rocks. The main contaminant of concern apart from the high metal loadings and acidic pH is the Cyanide; this occurs as it is the medium by which the gold is freed from its parent rock.
Clean Rivers trust in Romania in 1990 delivering aid and carrying out water research
In 2000 the Baia Mare mine in the Romanian Carpathians had a breach in their tailings dam that shed a vast loading of cyanide and metal rich muds into the local river systems, the media quickly showed across the world pictures of the hugh numbers of fish killed and spoke of the threat to the local and international rivers of Eastern Europe; including the River Danube.
The Rosia Montana scheme has attracted much bad feeling from the international environment movement, Friends of the Earth, Greenpeace, WWF and over 80 other organisations both European and in North America have raised the issue of the feer of a repeat of previous pollutions and the dislike of opencast operations as a method of winning minerals.
The realisation that the world needs metals that the earth yields up for exploitation for the benefit of local, national and international markets.Romania needs the benefits that a buoyant metals market can convey for the economy; the local population will benefit from the creation of jobs and services that will be brought into the area. Water, electricity and improved health infrastructure are all anticipated.
This short paper addresses the metals / cyanide issue and outlines a way forward to make the planned aqueous discharges from the mining operation a model of sustainable water management.
The volumetric quantities of water leaving the mine with a high metals concentration (sample analysis seen) are not known at this date, as noted, the expected concentrations of the metal loading are known and the methods for their removal have been evaluated. There is one treatment technology that has shown that it is able to address the metals at the anticipated loadings at the same time adjusting the pH from an acidic flow of pH 2.5 – 3.5 to a treated pH 9. The waste water at this treated stage would have high Sulphate loadings and concentrations of Cyanide.
Clean Rivers Trust has been asked by Virotec Europe, the metal removal and pH adjusting technology company to consider ways of removing the Cyanide and lowering Sulphates(>3000 ppm to <600 ppm) to acceptable levels. The prefdered treatment method would be a wetland system that could address the two pollutants.
Wetland Treatment of Cyanide and Sulphates.
The proposal is achievable; though the design and makeup of the substrates and flora would need to be site specific. Climate considerations as to frost, rainfall and draught; physical location of such a construction, the size and location of the whole would need to be fitted into the space that could be available. Daily maximum flow rates and the variation of Cyanide concentration, batch treatment or tailings diluted. Will there need to be toe drain or seepage discharge treatment capability? Further, the proximity of the habituations of the local population needs to be considered. The security of the site of the wetland would need consideration to make sure that boar or other wildlife that would be drawn to the site was excluded.
Consideration needs to be given to eco-toxicological issues and the protection of bacteria.
The treatment would need to take into account that there is a volatilisation of the Cyanide as it is moved in solution of water (boils at 27 degrees C in solution with water). The cyanide would, by the end of the process be broken down by biodegradation and oxidation; encouraged by bacteria within the wetland biosphere. The residuals would be Cyanates, Ammonia and Nitrate. These would also be decomposed by the end of the wetland processes.
The loadings of Sulphate are not of levels unknown in any other mining site of a similar character. The residue would be locked into the substrates of the wetland.
There are already some design needs that can be stated as requirements of the design.
• Low head feed of waters into the wetland.
• Area of wetland needs to ensure maximum residence time.
• The selection of regional flora and the sourcing of the same.
• Water distribution methods to avoid effluent accessions on distributor mechanisms
• The site engineering; terracing, spill-ways and discharge points to last the life of the opperation’s life time.
The proposal to remediate the discharge waters of the Rosia Montana Mine is a feasible project for the use of wetland methodologies. The only caveats are at present, knowledge based; areas available, the total volumes involved, and the engineering capabilities on site. This last issue is important in working out the civil engineering needs that may have to be brought in and can significantly affect costs.
Clean Rivers Trust is confident that this site can demonstrate good environmental credentials and demonstrate sustainable practices in protecting it. The Trust respectfully requests a visit to the site, so as to understand the physical layout and the general lie of the land.