Phyllite, quartzitic and micaceous schists
Metamorphic schists (phyllite, quartzitic and micaceous) are used in the building construction as the major component of a fine gravel cover of roll tar paper (phyllite and micaceous schists), in an agriculture as inert dust carrier of pesticides (phyllite and micaceous schists), and in the manufacture of fire-proof materials as one of the major components of a fire-proof cement (quartzitic schists).
Three deposits of phyllite schists are documented within 3 deposits in Opolskie Voivodeship (map): Chomiąża, Dewon-Pokrzywna and Dewon-Pokrzywna 2. The total anticipated economic resources of phyllite schists amounted to 15,901.39 thousand tonnes as of 31.12.2020. Similarly to the previous years, the exploitation was carried out only from Dewon-Pokrzywna deposit – it was equal 170.02 thousand tonnes and increased by 20.51 thousand tonnes in comparison with 2019 (it means the drop was 13.72%). The anticipated economic resources of this deposit decreased – due to the exploitation, losses and the better deposit exploration – by 285.40 thousand tonnes (2.10%) and were equal 13,328.35 thousand tonnes. Two other deposits of phyllite schists have not been exploited.
Figure below shows changes in domestic resources and production of phyllite schists in Poland in the years 1989-2020.
Quartzitic schists occur within the Strzelin granite massif in Dolnośląskie Voivodeship. The only one documented and temporarily exploited deposit of that raw material in Poland is Jegłowa deposit. Therefore, it should be particularly protected. Its anticipated resources (beyond protective pillars) in 2020 were equal 8 667.21 thousand tonnes and economic resources 2,736.25 thousand tonnes. The raw material output in 2020 was more than twofold bigger than in 2019 and amounted to 14.18 thousand tonnes. Therefore, the anticipated economic resources of the raw material in Poland dropped by 0.16%, whereas the economic resources by 0.50%.
Figure below shows changes in domestic resources and production of quartzitic schists in Poland in the years 1989-2020.
In the latest edition of The balance of prospective mineral resources of Poland, there was the assessment of resources prospective for quartzite and quartzitic schists in Poland updated*. The main criteria adopted for establishing the quartzite and quartzitic schists deposits were: the deposit thickness (minimum of 5 m), the overburden thickness to the deposit thickness ratio (maximum 0.5), the SiO2 content (minimum of 95%), the Fe2O3+TiO2+alkali content (maximum of 1%). As the result of such attitude, the prospective resources of quartzitic schists were assessed to be equal 8.49 million tonnes within 1 area which is strictly connected to the already documented Jegłowa deposit (the so-called layers from Jegłowa). To the prospective resources there were also the deeper parts of Jegłowa deposit included, together with the minor area of the schists outcrop west of Jegłowa deposit.
Micaceous schists have been documented within two deposits located in Dolnośląskie Voivodeship: Jawornica deposit in Kłodzko County and Orłowice deposit in Lubań and Lwówek Śląski Counties. The total anticipated economic resources of the raw material as of 31.12.2020 were estimated at 6,638.79 thousand tonnes and economic resources at 3,025.40 thousand tonnes. The resources of Orłowice deposit account for 85.61% of anticipated economic resources and 82.95% of the economic resources. Both the total anticipated economic resources and the economic resources of the raw material decreased in comparison with 2019 by 9.20 thousand tonnes due to the output from Jawornica deposit. In 2020, after several years of the continuous exploitation, the exploitation from Jawornica deposit was not carried out.
Figure below shows changes in domestic resources and production of micaceous schists in Poland in the years 1989-2020.
Prepared by: Marcin Tymiński
* Brzeziński D., Galos K., 2020 - Kwarcyty, piaskowce kwarcytowe i łupki ogniotrwałe (quartzite, quartzitic sandstone and quartzitic schist). In: Bilans perspektywicznych zasobów kopalin Polski wg stanu na 31.12.2018 r. (eds. Szamałek K., Szuflicki M., Mizerski W.): 305-308. PIG-PIB, Warszawa [in Polish].