Die Aufbereitung von Wolframerzen unter besonderer Berücksichtigung der flotativen Anreicherung von Scheelit

Translated title of the contribution: The processing of tungsten ores with particular consideration of the concentration of scheelite by means of flotation

Wolfram Bernhart

Research output: ThesisDoctoral Thesis


Tungsten, which is one of the high performance materials, plays an important role in the everyday life. After years of steady increasing production rates, in 2007 the world consumption of tungsten reached 77.000 t, a further increase of the demand is expected during the next years. 75% of the total annual tungsten production is used as pure metal or as tungsten carbide. The recycling rate is estimated to reach 30%. Based on the consumption data from the year 2007, some 55.000 t of tungsten metal have to be produced from natural resources by mining, concentrating and refining. The tungsten minerals of economic importance, used for the production of the various tungsten products are Wolframite and Scheelite. Wolframite, the iron-manganese-tungstate occurs coarse grained and coarse intergrown with the gangue minerals in the orebodies, mined today, whereas Scheelite, the calcium tungstate is finely disseminated in the ore. Due to the more advantageous processing characteristics of Wolframite, the mineral can be processed in a wide particle size range by means of gravity and high intensity magnetic separation techniques. Scheelite has to be concentrated by applying fine particle separation methods like gravity separation using tables, Humphrey spirals or flowing film concentrators or flotation, a physical - chemical process, utilising the different wettability of the minerals. The separation of Scheelite from gangue minerals like Calcite, Apatite, Fluorite, Dolomite, Magnesite, or Baryte, which are known under the synonym of sparingly soluble or alkali earth minerals and which occur in many times higher concentrations in the orebody, pose numerous problems to the mineral processing plants, which have to produce concentrates of acceptable quality and at high recovery levels. The collectors used in the processing of Scheelite by means of flotation have a very high tendency to be adsorbed on the mineral surface of the alkali earth minerals. Therefore complex collector depressant modifier systems have to be applied to achieve a more selective separation of Scheelite form the gangue minerals and to produce concentrates of more satisfactory quality for the refining plants. The scope of the present work was to investigate the state of the art in the processing of tungsten ores and to compare the different applied processes. The result should be the basis for the further development of the mineral processing techniques in the field of the beneficiation of tungsten bearing ores.
Translated title of the contributionThe processing of tungsten ores with particular consideration of the concentration of scheelite by means of flotation
Original languageGerman
  • Sitte, Werner, Co-Supervisor (internal)
  • Steiner, Hans Jörg, Supervisor (internal)
Publication statusPublished - 2007

Bibliographical note

no embargo


  • tungsten
  • scheelite
  • wolframite
  • flotation
  • sparingly soluble minerals concentrates

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