Kaolinite clays called as refractory clays are an indispensable raw material for production of fire resistant materials. Such clays originate in result of wash down of outcropping and near-surface kaolinized rocks and redeposition of kaolinite, connected with separation of quartz grains and marked improvement of fire resistance properties of that raw material.
Kaolinite clays are characterized by high plasticity and when fired at temperatures over 1,500oC they form ceramic bodies with high mechanical strength. Very low content of calcium and magnesium compounds is very advantageous as it results in a rise of melting point of these clays. In turn, presence of iron compounds results in yellow to brownish and red color of the refractory clays.
The single exploited deposits of refractory clays (the Rusko-Jaroszów deposit), is situated in the Lower Silesian region.
Refracotry clays deposits are presented on the map.
Table 1 shows the current state of exploration and development of the fireproof clay resources.
Anticipated economic resources amounted to 54.47 million tonnes in 2014 and were by 0.09 million tonnes lower than in 2013.
Economic resources were equal 1.73 million tonnes (3.2 % of total anticipated economic resources and 62.7 % of anticipated economic resources within exploited deposits).
In 2014 production of refractory clays was equal 83 thousand tonnes and decreased by 4 thousand tonnes in comparison with the previous year. The exploited raw material may be used without any processing or after firing, as the so-called “fired clays”.
PGE Górnictwo i Energetyka Konwencjonalna SA (PGE GiEK SA) informed that the exploitation of refractory and ceramic clays from non-documented deposits (so-called exploitation points) in the KWB Turów Mining Plant amounted in 2014 to 5.25 thousand tonnes.
Prepared by: Marcin Tymiński