Within the scope of this master thesis the technical possibilities to decrease the silica content below 1 m% in the ore concentrate of the Steirische Erzberg were investigated. A mineral raw material´s analysis on an average sample of the final ore concentrate provided the data set to select the correct maximum size for the subsequent magnetic HGMS separation tests on a lab test rig. The results of the systematic separation tests were compared with the separation efficiency of the industrial scale separator in the plant of the Steirische Erzberg. The liberation analysis comprising size-, density and susceptibility analysis combined with optical mircroscopy and SEM shows, that even the Spateisenstein concentrates of highest purity in the size class -100 + 40 µm have small quartz inclusion (< 2 µm). The best results on the lab matrix separator in the size range – 100 µm revealed a magnetic product of a SiO2 content of 2,26% and a Fe2O3 recovery of 44,72%. Settings can be found that match with the separation characteristic of the industrial scale separator in the plant of the Steirische Erzberg.