The Czech Geological Survey was granted the patent PV 2018-357, in force as of 31 December 2020, for processing graphite raw material. The principle of the patent consists of using ultrasound in the processing of graphite raw material after first being separated by flotation.

Graphite raw material is usually processed by crushing and grounding to a required grain size, thereby often causing the breaking of tabular graphite crystals, referred to as flakes.

By contrast, the use of ultrasound allows the planar separation of graphite flakes from mica and clay minerals with which graphite forms a natural composite. Therefore, this method significantly enhances the efficiency of flotation separation of graphite. Moreover, it increases the graphite concentration in the flotation concentrate and its quality, with fewer flotation cycles. The process was primarily developed for graphite raw material that is difficult to beneficiate, in particular where the graphite concentrate contained a large amount of inorganic admixtures even after several cycles of flotation separation. Thanks to this process, some graphite deposits, considered as non-prospective due to demanding raw material beneficiation, can once again become economically promising. The attached animation illustrates the simplified principle of the patent.

The team of specialists from the Czech Geological Survey, developing the patent, was represented by František Pticen, Michal Poňavič, Bohdan Kříbek and František Veselovský.