The Sturec gold project in central Slovakia is an underground gold and silver mining operation being developed by MetalsTech.
Gold mining began at Sturec in the 8th century with historical production from the mine totalling 1.5 million ounces (Moz) of gold (Au) and 6.7Moz of silver (Ag). The majority of the production was from underground mine workings, although some of it was from small open-pits.
The gold mine was purchased by Ortac Resources in 2009 and a pre-feasibility study (PFS) for the project was released in 2013. Based on the PFS, the mine is expected to produce up to 1.5 million tonnes per annum (Mtpa) with an average grade of 1.7g/t Au and 14g/t Ag.
In February 2020, MetalsTech purchased a 100% interest in the Sturec project by exercising an option to purchase Ortac Resources (UK).
Background on project approvals and challenges
Ortac received approval for a small-scale underground mining application in 2014 and began trial underground mining at the mine in June that year. The mine development activities were halted in 2014 after the Slovakian Government banned the use of the cyanide-based gold recovery process.
A regional court revoked the regulator’s decision to award the mining permit in 2016, following which the regulator issued an amended underground mining permit paving the way for the restart of small-scale mining activities in July 2017.
The Central Mining Bureau issued an extension to the existing underground mining licence in October 2019, which was challenged by the local community. The State Mining Administration quashed appeals against the decision to issue the permit in February 2020.
The extension allows MetalsTech to undertake mining at the Kremnica Mining Licence for the period between 2019 and 2021.
In July 2020, MetalsTech started underground diamond drilling within the Andrej Adit at the Sturec mine.
Sturec gold project location, geology and mineralisation
The Sturec gold project is located between Kremnica and the village of Lúčky in central Slovakia and 17km west of Banska Bystrica. It is situated within the Kremnica Mining Licence area, which occupies 9.47km² of land. The mineralisation at Sturec is a low-sulphidation epithermal Ag-Au deposit style characterised by Tertiary andesite flows and tuffs.
The deposit has continuous mineralisation for 1.2km at main zone. The mineralisation is between 100m and 150m deep, open in all directions, and reaches to a depth of more than 300m.
Sturec gold project reserves
According to the 2013 PFS, the Sturec gold project is estimated to contain 13.9Mt of proven and probable ore reserves containing 765koz of gold graded at 1.7g/t of Au and 6,385koz of silver at 14.2g/t of Ag.
The project contains a mineral resource of 21.2Mt graded at 1.5g/t Au and 11.6g/t Ag containing 1.02Moz of gold and 7.94Moz of silver, based on JORC (2012) Resource estimate released in April 2020.
Mining and processing plans at Sturec gold project
The PFS considered the use of conventional mining methods of drill, blast, load, and haul.
MetalsTech is planning to complete the drilling programme to evaluate the extension of the deposit in high-grade zones in the near term. The ore from the mine will be sent for metallurgical testing and potential toll treatment of ore for cash flow in the short term. The company entered an agreement with Clean Earth Technologies for use of the latter’s cyanide-free thiosulphate-based gold recovery technology for metallurgical test work.
It is also working on securing further mining permits for potential expansion of resource at Sturec. Subject to a successful exploration campaign, the company will also work on an updated PFS that will include a revised strategy for mine management and processing. The Cycladex process was also studied as a possible processing technique in place of cyanidation.
Snowden Mining Industry Consultants prepared an updated mineral resource estimate report for the Šturec deposit in 2012. The report was reviewed by SRK Consulting, which also completed the PFS for the project in 2013.
GBM Minerals Engineering Consultants was contracted to perform flowsheet development and engineering design of the processing plant for the PFS.