The fluorite losses in the tailings of the processing plant in Wolfach, Germany, have been known for a long time and were the aim of numerous investigations accomplished by many research institutions. These investigations focused mainly on the centrifugal force density separators, i.e. Tri-Flo-separators, which were blamed for the fluorite losses so far. Within the scope of a joint project between Sachtleben Bergbau GmbH (Ltd) and the Department of Mineral Processing of the University of Leoben, the detailed investigations accomplished in this thesis disproved the assumption that either the separator itself or its operational mode causes the fluorite losses. In fact, an accurate characterisation of the mineralogical composition indicated that the partly highly developed porosity, which could be observed in a considerable part of the fluorite, was the reason for the fluorite losses. The mainly experimental investigations were divided into three parts of test work, the field tests in the dense media separation plant, the gravity separation tests and the search for alternative separation methods. The field tests in the dense media separation plant in Wolfach together with systematic investigations at the laboratory of the Department of Mineral Processing should give information about the separation devices – i.e. two Tri-Flo-separators – and their influence on the processed ores. The gravity separation tests including feed preparation by classification were accomplished as well as the implementation of a spiral separation plant in the processing plant to ensure a pre-sorting of the material with a grain size smaller than 1.6 mm. The third part contained the search for alternative separation methods, which do not use density differences for separation, because the investigations concerning the porosity of the fluorite showed that any density separation will implicate fluorite losses in the tailings. Electrostatic separation was found to be the best alternative method in contrast to the gravity and dense media separation. By this method, high grade barite and fluorite products and tailings without mentionable losses could be produced. Furthermore, the porous fluorite can be recovered by this separation method. Therefore, in addition to the discovery of the cause of the fluorite losses, a possible solution for this problem could be presented.