Diversified company MetalsTech (ASX: MTC) has delineated a mineral resource of more than 1 million ounces gold at its flagship Sturec project in Slovakia and will re-commence mining from the project’s Andrej adit this month.
The resource has been reported as 21 million tonnes at 1.50 grams per tonne gold and 11.6g/t silver for 1.026 million ounces gold and 7.94Moz silver, using a 0.4g/t gold cut-off grade within an optimised open pit shell.
Underground, the project is believed to host 388,000t at 3.45g/t gold and 21.6g/t silver for 43,000oz gold and 270,000oz silver, at a 2.85g/t gold cut-off.
The figures are based on 90.5% gold recovery rates on Sturec mineralisation using proprietary cyanide-free ammonium thiosulphate gold processing technology developed by Clean Earth Technologies (CET).
The use of cyanide-based gold recovery has been banned in Slovakia from 2014 and thiosulphate has become an attractive alternative as it is non-flammable, water soluble and negates the need for toxic lixiviants during processing.
MetalsTech chairman Russell Moran said Sturec’s mineral resource had been a positive boost to progress at the historic project.
“A million ounces of gold is a great start, and we are particularly pleased the estimation was completed using gold and silver recovery rates taken from the thiosulphate testing,” he said.
“In order to commercialise Sturec to its fullest potential, we need to demonstrate that the operation can be economic with a lixiviant other than cyanide.”
Following an extension to Sturec’s underground mining permit, MetalsTech will restart mining at the existing Andrej adit with ore set to undergo further thiosulphate testing under a co-operation agreement with CET signed in February.
CET owns the extraction technology which was developed over more than 10 years by Australia’s Commonwealth Scientific and Industrial Research Organisation.
In 2014, the CSIRO collaborated with Barrick Gold Corporation to implement the technology at the Goldstrike mine in Nevada which now produces approximately 350,000oz gold each year for Barrick and Newmont Corporation (under the Nevada Gold Mines joint venture).
Sturec’s Andrej adit is reported to be readily accessible and last week MetalsTech commenced preparatory works including the delivery of ore extracting equipment.
Once the preliminary ore has been extracted from Andrej, additional material will be mined for stockpiling and potential toll treatment by nearby gold producers.
The historic Sturec project is located in central Slovakia and consists of the Kremnica mining licence over 11.8 square kilometres and the broader Lutila exploration licence over 63.1sqkm.
Gold mining commenced at Sturec in the 8th century and historical production is believed to have totalled approximately 1.5Moz gold and 6.7Moz silver, mostly from underground workings.
It is considered an advanced asset with an existing pre-feasibility study completed in 2013.
MetalsTech entered the gold space when it acquired 100% of Sturec in November from Arc Minerals Ltd and its subsidiaries.