SPS completes mine water treatment project in Slovakia

Mining operations worldwide are playing a significant role in the use of valuable fresh water supplies. As the global climate changes and we face drought situations for increased months across a wider range of countries, the careful management of such water resources becomes even more important. Indeed, to meet regulatory, environmental and social requirements, the mining industry must focus its attentions on reducing energy consumption, recycling and re-using water in its operations, meeting discharge consents and minimising waste.

The latest such project can be found at Strieborna, near Roznava, eastern Slovakia – a town which has a mining heritage dating back to the Middle Ages. Canadian mining company Global Minerals has been operating the high grade silver-copper-antimony vein at the Bana Maria mine, Strieborna, since early 2011. In mid-2011, Global Minerals contracted SRK Consulting to develop a temporary water treatment facility for the removal of iron and manganese during the mine dewatering process. Specialist industrial water treatment solutions provider, Siltbuster Process Solutions (SPS), was brought on board to design, fabricate and install the mine water treatment plant at the end of 2011.

Global Minerals' CEO William Pincus explained: "Having successfully completed a programme of exploratory drilling, we needed to pump over one million cubic metres of contaminated water out of the mine to allow access for the commencement of silver and copper mining. Our consultants, SRK, recommended active (chemical) treatment of the mine water and suggested we contact SPS to discuss the possibility of providing a turnkey solution."

SPS, which is based in Wales, has a strong pedigree of mine water treatment feasibility studies and plants in the UK, Greece, Canada, France and Australia. In fact, the Welsh company was responsible for one of the world's largest active mine water treatment projects at Wheal Jane, Cornwall, UK, which has treated in excess of 100 million cubic metres of water over the last decade. More recently, SPS won the 2010 Edie Award for the best water treatment plant in the UK for its design of the Dawdon Mine water treatment plant for the UK Coal Authority.

Clwyd Jones, business unit manager at SPS, commented: "SPS has developed a reputation for providing emergency water treatment facilities for the municipal and industrial sectors throughout the UK and Europe. Consequently, the Global Minerals project provided us with the ideal opportunity to combine our expertise in mine water treatment with our experience in the rapid deployment of water treatment solutions."

Following project award in October 2011, SPS completed the design, fabrication and installation of the Roznava mine water treatment plant within just 14 weeks. The facility was formally handed over to the client in February 2012, and can handle up to 100 cubic metres of iron and manganese-laded water being pumped out of the Bana Maria mine every hour.

SPS technical manager Dr Chris Bullen explained: "Designing a treatment plant for mine dewatering can be a challenge, as you can never be completely sure of the actual water quality until pumping commences. It is not unusual for the mine water to be stratified with relatively clean water from the infiltration of precipitation overlying more heavily contaminated deep mine water. The Bana Maria project saw early data indicate that no more than 50mg/l iron and 10mg/l manganese would need to be removed. However, on commencement of pumping, this rapidly rose to 220mg/l iron and 80mg/l manganese. Having previously experienced this scenario on other mine water projects, the SPS design incorporated sufficient flexibility to cope with the variation. We were able to rapidly reconfigure the system to cope with the additional sludge volume generated by the increased metal concentrations."

The complete plant was fabricated by SPS in the UK; using reaction tanks based around 20' ISO shipping containers and lamella clarifiers from the existing SPS range. The equipment was transported to site on articulated lorries, with installation and commissioning of the plant undertaken over a three week period by SPS and German partner USG. The contractors on site were faced with unusual conditions, as harsh weather hit Eastern Europe and temperatures dropped to as low as minus 20 degrees centigrade overnight. However, the ambient temperature of the mine water was a fairly constant plus 10 degrees centigrade, and so the challenge was minimised once the plant was up and running. Martin Zahores, CEO of Gemer-Can sro – the Slovakian subsidiary of Global Minerals, praised the installation teams, thanking them for their "excellent work in those harsh conditions" and stating that they had "helped remove a major headache for us."

The local economy at Roznava is founded on its mining heritage and expertise. Clwyd Jones of SPS said: "The rapid deployment of the SPS mine water treatment plant allows for much quicker dewatering of the mine and the commencement of silver and copper extraction. This will create a significant number of jobs in what has been an economically depressed area for many years. This project can be seen as a win-win situation for everyone involved."

Global Minerals controls approximately 135 square kilometres of exploration concessions around the Strieborna area. The project location has existing infrastructure, including electrical power, paved highways, railway access and a local workforce experienced with underground operations. The mine programme is on track to have all facilities ready for underground exploration and development on completion of the dewatering project. All major electrical systems have been updated, as well as upgrades to the shaft, haulage tunnel and pipelines. Additional renovations to some of the surface buildings are underway to provide office space, service and change areas for the increasing on site activities.