Leucogranites that are exploited at Krasno - Vysoky kamen deposit (Krasno ore district, Slavkov crystalline unit, western part of the Bohemian Massif, Czech Republic) are used as a feldspar raw material. These rocks are product of hydrothermal metasomatic alteration of Variscan granites.
As the exploited material is utilized mainly by ceramic and/or glass industries, the content of harmful colourants presents a critical issue. Laboratory and small-scale processing trials by combination of magnetic and gravity separation aimed in reduction of the content of harmful phases.
Mineralogical and chemical analyses of the obtained waste have shown that it is enriched in phases with high concentration of elements such as Li, Nb, and/or Ta which are considered as critical raw materials in EU.