Overview
The Certej gold-silver project covers an area of 2,670 hectares and is located 12 km northeast of Deva, a city located in Hunedoara County of Transylvania, Romania.
The concession is held by Deva Gold a European Goldfields wholly-owned subsidiary.
Documented gold mining in Transylvania dates back more than 2,000 years and to date some 40 million ounces have been extracted from the 'Golden Quadrilateral' region.
Gold mining in the Certej area dates back several hundred years. Modern mining took place between 1970 and 2007 when the last open pit was closed.
The Certej deposit is a disseminated and breccia hosted gold-silver deposit that would be mined by open pit mining methods at a strip ratio of 3.1:1.
The project has 16 years of mine life and would produce 47.0 Mt of ore for some 160,000 oz gold and 800,000 oz silver annually.
The process plant would comprise a 9,500 tpd concentrator where the refractory ore would be subjected to flotation and to a subsequent Albion oxidation process while the gold would be recovered by a CIL process.
The project would employ about 300 people from the Certej area.
Location
Romania is a European Union country of 238,391 square kilometers located in Eastern Europe. It embraces the Carpathian Mountains and is bordered by the Danube River and the Black Sea. It boasts a population of 21.5 million people most of them are speaking Romanian a language (related to Italian, Spanish, French, and Portuguese) which was derived from Vulgar Latin.
Transylvania, 'the land beyond the forests' in Latin, is a historical region originally inhabited by the ancient Dacians, a proud people conquered by Roman Legions attracted by the land's rich gold endowment ? their booty was 5.3 million ounces of gold and 10.6 million ounces of silver. The Romans brought mining experts and started many open pit and underground mining operations and the 2,000 year old works could still be visited today in the Rosia Montana area.
The world's oldest gold artifacts (4,000 years old) have been found in Eastern Europe and the gold most likely originated from the same place ? i.e. the Transylvanian Alps.
Close to the project at Sacaramb (a type locality) several gold-silver telluride minerals have been recorded there for the first time ? e.g. 'petzite'.
The Certej gold property is located 12 km NNE from Deva a 69,000 people city located in the Hunedoara County, Romania. It can be accessed by the national highway E68 from Deva. The National Railway system and roads connect Deva with the rest of the country and the Black Sea port of Constantza.
The project is part of the Southern Apuseni Mountains and is characterized by hills reaching a maximum of 600 m in elevation. A major river, the Mures runs within 10 km of the proposed mine site. While small rural settlements are nested in the hills, no human settlement is going to be affected by the proposed mining project.
The climate is mild temperate-continental and exploration and mining activities could continue throughout the year with no problems.
Geology
The exploitation license lies within the southern Apuseni Mountains which are part of the Carpathian-Balkan geological province of the Tehyan Arc.
The mining district hosts numerous epithermal and mesothermal Ag-Au, Cu-Au and Cu, gold, silver and base metal deposits associated with the Neogene andesitic-dacitic volcanic and sub-volcanic bodies which are intruded into a variety of lithologies.
The Brad-Sacaramb Neogene volcanic belt occurs within a major northwest-southeast trending graben which is approximately 20 kilometres long and 10 kilometres wide. The basement in the Certej area on either side of the graben has been mapped as basalt of Jurassic age.
The Certej licence is dominated by extrusive and intrusive andesite.
The deposits along the Certej Brad belt are classified as low to medium sulphidation epithermal deposits. The Certej deposit itself is mid- to shallow-level and has been driven by hydrothermal fluids probably of a mainly magmatic origin.
The gold endowed region known as the 'Golden Quadrilateral' has to date produced some 40 million ounces of gold.
The main mineralized zone is some 1,500 meters long by 500 meters wide and occurs as sub-horizontal, to moderately dipping zones hosted by Cretaceous and Neogene sediments with andesitic rock intrusions.
The deposit hosts four distinct types of mineralization characterized by individual chemical and mineralogical signatures. Gold is mostly refractory.
Total reserves were estimated at 47Mt containing 2.41 Moz gold and 17.3 Moz silver and will support a mine life of 16 years.
Mining & Operations
The Certej Project will be mined by conventional open pit, selective mining exploitation method. The mining method is a conventional open cut drill, blast, load and haul operation, using hydraulic excavators to carry out selective flitch mining, similar to many small open pit gold mining operations throughout the world, and off-highway dump mining trucks.
Mining and equipment maintenance will be carried out by owner.
Drilling and blasting will be performed on 5 m high benches, with blasted material excavated in two discrete flitches, each nominally of 2.5 m height.
Based on the optimisation work, 4 pits have been designed, namely Starter East, Starter Central, East and West. A pre-strip period of almost 9 months is envisaged during which 8.2 Mt of waste is removed and 764 kt of ore are stock piled.
Mining and support units consist of: Three Rotary percussion drill rigs (120-200mm diam. Holes); Two 8.5 m3 hydraulic excavators; Twelve 62t off-highway rear dump trucks; One 500 kW wheel loader; Three 300 kW track dozers; One 300 kW wheel dozer; One 150 kW motor grader; One 120 kW integrated tool carrier; One water truck; One fuel and lube truck.
Processing
The process plant will comprise a conventional 9,500 tpd concentrator with crushing, grinding and sulphide flotation unit operations. The refractory gold and silver bearing sulphide flotation concentrate will then be directed to the Albion Process plant where the (pyrite sulphide) concentrate will be oxidized and the solid residue will be directed to the CIL and precious metals plant to recover the liberated gold and silver as a dore.
The Albion Process is a combination of ultra-fine grinding of concentrates followed by oxidative leaching at atmospheric pressure. The process does not employ autoclaves or rely on bacterial cultures. The residues from the flotation and gold plants will be disposed of in two separate but adjoining TMFs, Tailings Management Facilities.
The crusher has a design capacity of 434 tph. The SAG mill would be rated at 2.5 MW and have variable speed control and the Ball Mill will be driven by a fixed speed 3.5 MW motor.
The rougher concentrate will be collected in a series of launders and pipes, and will report to the 1st Cleaner bank of 4 x 30m3 cells. The product from the 1st Cleaner will report to the 2nd Cleaner bank of 4 x 20m3 cells and then to the 3rd Cleaner bank of 3 x 20m3cells.
The gold and silver bearing final concentrate slurry from final stage cleaner flotation cells will be pumped to the concentrate thickener feed box and then to a 10m diameter high rate thickener.
The IsaMill is a horizontal high speed stirred mill that achieves power intensities of up to 350 kW/m3. Inside the shell, rotating grinding discs are mounted on a shaft which agitates the grinding media and ore particles. The media that is used in the mill is generally ceramic beads or silica sand.
The Albion residue will be thickened in a 20-m diameter high-rate thickener.
The gold recovery plant is a standard type CIL plant. The elution section will treat carbon from the CIL circuit to remove gold and silver and is based on the widely used AARL system. A standard system of electro-winning will be used to recover gold and silver from solution. The CIL tailings would be detoxified.
The project is scheduled to produce an average of 308,000 tonnes of flotation concentrate per annum with high grades between 17 ? 19 g/t gold and 80 ? 130 g/t silver, depending on the source of the ore in the deposit.
A total of 40.5 million tonnes and 10.5 million tonnes of Flotation and CIL tailings respectively will be produced during the life of the mine. The production rate will be respectively 2.7Mtpa and 700,000tpa for the Flotation and CIL TMF.
Electrical power to the plant will be supplied from the existing 110 kV overhead transmission line from Paulis to the old Certej processing plant.
The Certej flotation tailings dam will be a homogeneous rock fill structure with a capacity of 27 million m3.
Annual metal production will average 160,000 oz of Au and 800,000 oz of silver.
