Magnesites

Magnesite (magnesium carbonate - MgCO₃) originates from 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, six 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.

Table 1. Magnesites - million tonnes

Anticipated economic resources as of the end of 2016 were estimated at 13.92 million tonnes and decreased due to the exploitation by 0.08 million tonnes in comparison with the previous year.

In 2016, the domestic production (from Braszowice deposit under exploitation) of magnesite was equal 78 thousand tonnes and decreased in comparison with 2015 by about 20% (table 2). It was the first year of the production declining, after three years of the output remaining at the similar level of about 90 thousand tonnes.

Table 2. List of magnesites deposits - thousand tonnes

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.