Kaolinite clays called as refractory clays are an indispensable raw material for the production of aluminosilicate fire resistant materials. They are also used for the production of ceramic tiles and sanitary articles. Such clays originate in the 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 a high plasticity and when fired at temperatures over 1,500oC they form ceramic bodies with a high mechanical strength. A 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, the presence of iron compounds results in yellow to brownish and red color of the refractory clays.
The single exploited deposits of refractory clays (Rusko-Jaroszów deposit), is situated in the Lower Silesian region. The second largest deposit is called Kryzmanówka and is located in Mazowieckie Voivodeship.
Refractory 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 54.31 million tonnes in 2016 and decreased by 0.06 million tonnes in comparison with 2015 due to the exploitation from Rusko-Jaroszów deposit (0.08 million tonnes) with resources growth in this deposit equal 0.02 million tonnes.
Anticipated economic resources covered by the detailed exploration (in A+B, C1 categories) were equal 53.63 million tonnes and accounted for 98.7% of total anticipated economic resources.
Economic resources were equal 1.59 million tonnes (2.9% of total anticipated economic resources and 60.7% of anticipated economic resources within exploited deposits).
In 2016 the production of refractory clays was equal 75 thousand tonnes and decreased by 12 thousand tonnes (13.8%) in comparison with the previous year (table 2). 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 2016 to 3.50 thousand tonnes.
The figure given below shows changes in domestic resources and production of refractory clays in Poland in the years 1989-2016.
Prepared by: Marcin Tymiński