Magnesite (magnesium carbonate - MgCO3) originates from a decay of magnesium-rich igneous rocks under hydrothermal conditions and forms white accumulations.
Polish magnesite deposits are related to the Sobótka, Szklary, Grochowa-Braszowice massifs of Precambrian serpentinites and the Gogołów-Jordanów Massif of ultramafic rocks in the Lower Silesian region (map). Up to the present, 6 magnesite deposits have been documented in this region. The deposits are of the vein type, with individual veins attaining up to 3 m in thickness and characterized by a complex geological structure and a high variability in the raw material quality. Magnesite is currently exploited in an open strip mine at Braszowice only. Prospective resources are assessed to be equal 3.25 million tonnes*.
Magnesite is used mainly as a semi-manufactured material in the production of multi-component artificial fertilizers, in the purification of potable water and sewage treatment and as a mineral additive to animal feed.
Table 1 shows resources and the state of development and exploration of magnesite deposits in Poland.
Anticipated economic resources as of the end of 2017 were estimated at 13.82 million tonnes and decreased due to the exploitation by 0.10 million tonnes in comparison with the previous year.
In 2017, the domestic production (from the only deposit under exploitation - Braszowice) of magnesite was equal 102 thousand tonnes and increased in comparison with 2016 by about 30% (Table 2). It was the first year of the production exceeding 100 thousand tonnes, after the output drop in 2016 and after 3 years (2013-2015) of the output remaining at the similar level of about 90 thousand tonnes.
The figure given below shows changes in resources and output of magnesites in Poland in the years 1989-2017.
Prepared by: Agnieszka Malon
*Sroga C., 2011 - Magnezyty. In: Bilans perspektywicznych zasobów kopalin Polski wg stanu na 31 XII 2009 r. (ed. S. Wołkowicz, T. Smakowski, S. Speczik): 228-231. PIG-PIB, Warszawa.