At the end of May 2019 the exploratory shaft of Saxony Minerals & Exploration AG (SME), Halsbrücke/Germany, above Pöhla, reached the tungsten deposits 175 m deep. A horizontal tunnel is currently being dug in order to mine even more ore from deposits. Since the beginning of September the pilot system for processing the ore mined from the shaft is now also running. The system, located in the Mittweida industrial park Lauenhain, digs out the tungsten rock delivered from Pöhla and also fluoride, also called fluorspar. As soon as the actual processing plant assumes its work on the mine site in Pöhla-Luchsbachtal, the operation of the pilot system in Pöhla ends and it is removed. It is then used again as an additional installation in Luchsbachtal.
“It is definitely a good decision that we played through the ore processing in a pilot system first”, reports Klaus Grund, Mine Surveyor, also on the Planning, Technology and Strategy Board of the SME. “Here in Mittweida we are continuously optimising the treatment process and thus collecting important experiences, which help us in Pöhla to apply the best method. The determination of the perfect processing method is complex as in Germany polymetallic rock was last processed in 1988. As we are dealing with a polymetallic rock mixture, we naturally use degradable substances that are not in danger of contaminating the drinking water supplies in order to liberate the ores. We are currently improving the exact formula of the reagents.”
The use of the process has been carefully examined and approved by the responsible authorities of the district administration. “In contrast to the typical processes in the GDR era, when very strong acids were used, we pay close attention to environment protection and only use degradable substances”, adds Grund. A three-shift system is in place at the Mittweida plant with six workers on each shift. SME can process 3,000 t of rock in Mittweida up until the end of the approved system runtime at the start of September 2020.
A worthwhile venture because in the Pöhla extraction site significant reserves of tungsten, fluorite and tin await with a value of over 700 M €, proven by numerous explorations, including also in the GDR era by Wismut. In order to cover the enormous investment need of an underground mine incl. processing, SME has been issuing 5.5 year corporate bonds at an interest rate of 7.75 % since the middle of October this year.
“Not least because of the high raw material content, we will be in the top 25 % of tungsten mines in the world as far as costs are concerned and can therefore operate extremely competitively. We also help reduce Germany’s dependence on raw material imports”, says Grund. “Our bond is therefore not only a good investment, but it also supports Germany’s strategic interests.” (SME/Si.)
