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Fast Facts
Resource efficiency and circular economy
Country
Brazil
Funding period
01.04.2019 - 31.03.2022
Funding volume
1.053.041 €
Funding reference number
033R208A-C
Contact

Coordinator: Clausthal University of Technology, Clausthal Institute of Environmental Technologies (CUTEC)

Contact Peson: Graduate Engineer Sven Schulze

Address: Leibnizstraße 23, 38678 Clausthal-Zellerfeld

Phone.: +49 5323 72-6271

Fax.: +49 05323 933-100

Email: sven.schulze@cutec.de

 

Project partners

  • Institute for Geosciences and Natural Resources (BGR), Hanover
  • H.C. Starck Tungsten GmbH (HST), Goslar

 

Project partners in Brazil

  • Universidade Federal do Rio Grande do Norte (UFRN), Natal
  • Mineração Tomaz Salustino S.A. (MTS), Currais Novos
  • Equilibirum Engenharia e Meio Ambiente (EEMA), Porto Alegre
ReWoRK

Recycling Tungsten from Ore Concentration Residues

The conventional extraction of tungsten is associated with significant environmental impact. Among other things, large amounts of material residues, which accumulate in large-scale and often contaminated material dumps, are produced with current production methods. These often contain high concentrations of tungsten, which, however, usually remain unused. The German-Brazilian project ReWoRK is researching the technological processing of the dump material for material recycling and would like to contribute to the conservation of natural resources as well as the reduction of the environmental impact of mining.

Tungsten recovery from dump material

For a long time, tungsten ores such as scheelite have been processed exclusively by technological processes involving a considerable amount of unused material. This led to the accumulation and storage of immense amounts of fine-grained residues of processing material, so-called tailings. These often contain enough tungsten concentrations to be of economic and strategic importance. ReWoRK is working on process innovations for the development of resource-saving methods for tungsten recovery.

Professor Fabio Jose Pinheiro Sousa (r.) of UFRN together with project leader Sven Schulze, Graduate Engineer, at a dump from Mina Brejuí. © Sven Schulze, CUTEC
Professor Fabio Jose Pinheiro Sousa (r.) of UFRN together with project leader Sven Schulze, Graduate Engineer, at a dump from Mina Brejuí. © Sven Schulze, CUTEC

Today's systems often use processes that allow for significantly higher yields of the material. However, these systems have special site requirements, for example often require a large amount of water, which does not allow for economic operation in dry and arid regions. The processing of input materials with difficult compositions, for example with molybdenum content, is also not necessarily possible with these methods. Due to the lack of adapted processing technologies, older treatment processes and therefore lower material yield are still being used today at certain sites.

The ReWoRK project aims to close this research gap and provide suitable technologies for the extraction of previously unused tungsten content. To this end, the partner network covers the entire value chain from exploration of raw materials (BGR) through mines (MTS) and research facilities (CUTEC, UFRN, EEMA) to product production and recycling (HST). Brazilian and German partners are involved in the project.

Process development

The aim of the project is first to close the technological research gap for the treatment of the dump material. In the first step, dumps in Europe and Brazil will be explored and extensive samples taken. Further steps are process development in the laboratory, the production of tungsten ore concentrates with positive profitability forecast as well as the construction of a functional demonstration plant.

Implementation in multiple locations

The project results are to be implemented in Brazil (Currais Novos), but also in other possible locations. For this purpose, the processing technologies for the production of tungsten ore concentrate will be installed directly at the mine sites. In Brazil, modernisation of the technology used up to now is also planned based on the project results. In Germany, on the other hand, adjustments are planned to process the obtained concentrates, if necessary. In the long term, the processing technologies developed can also contribute to increasing the efficiency of future tungsten mines at other sites.

Sampling of tailings (fine fraction) for the preliminary investigations by Eng. L. Gomes Garcia (EEMA) (r.) and Professor Sousa (UFRN), Mina Brejuí 2018. © Sven Schule, CUTEC.
Sampling of tailings (fine fraction) for the preliminary investigations by Eng. L. Gomes Garcia (EEMA) (r.) and Professor Sousa (UFRN), Mina Brejuí 2018. © Sven Schule, CUTEC.

Increase in resource efficiency

By using secondary materials and increasing the yield in primary mining, it is possible to increase resource efficiency, thereby conserving natural resources. Due to the deconstruction of dumps, if additional by-products are recovered during reprocessing, released areas can be returned to another use or restored. Should there be further and possibly critical heavy metals in the spoil heaps, these could possibly also be removed from the material, thus preventing future environmentally relevant contaminations. With the use of tailings for tungsten extraction, further significant reduction in the environmental impact is to be expected, since the material is extracted and thus easily accessible, making elaborate mining unnecessary. But a reduction of the environmental impact is also to be expected by increasing the efficiency of primary mining.

From a strategic point of view, Germany's security of supply can be increased by broadening the available technologies and input materials for tungsten production.