Building ceramics raw materials
Mineral raw materials used in the industry of building ceramics are varying in age and origin. Raw materials currently exploited for the needs of that industry in Poland come from deposits ranging in age from the Permian to Quaternary. The deposits are distributed practically throughout the whole country. However, they are more common and larger in the south also their differentiation appears higher than in other parts of the country.
The main building ceramic products are: ceramic bricks and breezeblocks, slates, clinker bricks, ceramic pavements.
Main raw materials used for building ceramics production are clay rocks. Their suitability depends on their plasticity after they are mixed with water. If the plasticity is too high, the mix is corrected by adding such ingredients as sand, crushed brick and fly ash and sawdust. Clay and non-clay raw materials very often occur together - in one deposit.
Raw materials for building ceramics production contain clayey minerals. In loess clayey minerals content is low (couple of %), but in clays it can be 100 %. Usually the content is between 40-60 %. Other components are quartz sand and dust, feldspars, calcite and dolomite, iron minerals, mica minerals and organic matter.
The most important raw materials of the Quaternary age include stagnant lake sediments such as muds and clays occurring mainly in northern and central Poland as well as loess, glacial tills, alluvial sediments and those of weathering covers and sands. The most important raw materials of the Tertiary age include clays of the so-called Poznań Series from south-western and central Poland and those of the Krakowiec Clays from the area of the Carpathian Foredeep in south-eastern Poland. The Triassic and Jurassic deposits are situated at the margin of the Holy Cross Mts and in the Czestochowa and Opole regions. Building ceramics raw materials deposits in Poland are presented on the map.
According to the Regulation of the Minister of the Environment of the 22nd of December 2011 (number of Polish act: Dz. U. Nr 291, poz. 1712.) the limit values of the parameters that defines the deposit are: - the maximum documentation depth – to the depth of possible exploitation; - the minimum thickness of the deposit – 2 m; - the maximum overburden/thickness ratio – 0.5; the maximum content of grains bigger than 2 mm – 1 %; - the maximum content of ceramic marl with grains diameter bigger than 0.5 mm – 0.4 %; - the shrinkage in drying minimum 6 %. These limit values have not changed in comparison to the previous “balancing criterias” (obtaining since the 1st of January 2002 to 31st of December 2011).
The table given below shows reserves and the state of development and exploration of clay raw material for the building ceramics industry.
Anticipated economic resources amounted to 2,043.07 million m3 in 2014 (about 4,086.14 million tonnes) and decreased by 0.45 million m3 (about 0.90 million tonnes – 0.02 %).
There were 2 new deposits documented (+0.183 million m3): Barcik 10 in Mazowieckie Voivodeship (with resources equal 0.170 million m3) and Pniów-Bałdos I in Podkarpackie Voivodeship (with resources of equal 0.013 million m3).
There were also 22 new documentations approved for documented deposits – due to the exploitation ending or deposit boundaries changes.
There were 15 deposits crossed out of “The balance…” (-1.590 million m3): including: 4 deposits in Dolnośląskie Voivodeship (Pęgów, Proszówka, Słupiec, Trzebnica), 1 in Lubelskie Voivodeship (Kraśnik-Suchynia W), 1 in Małopolskie Voivodeship (Tropie Góry 2), 3 in Mazowieckie Voivodeship (Kobyłka-Maciołki DM, Marki Wesoła 57, Słupno-Wawrzynów 2), 1 in Opolskie Voivodeship (Skarbiszowice III), 3 in Podkarpackie voivodeship (Gorzyce-Korga, Wrzawy – Laskowski V, Zalesie Gorzyckie – Dul 6), 1 in Śląskie Voivodeship (Buków A) and 1 in Świętokrzyskie Voivodeship (Ruszcza I).
The boundaries changes caused the amendments of resources (+2.223 million m3) for: Kęty deposit in Małopolskie Voivodeship (-0.433 million m3), Janiszów deposit in Lubelskie Voivodeship (+0.015 million m3), Gaboń – Grabie in Małopolskie Voivodeship (+0.072 million m3), Pniów – Bera VIII (+0.004 million m3) and Wrzawy-Laskowski VI (+0.014 million m3) in Podkarpackie Voivodeship, Opalenie in Pomorskie Voivodeship (+0.514 million m3), Kolosy (+0.165 million m3) and Wyszyna Fałkowska III (+1.439 million m3) in Świętokrzyskie Voivodeship.
The resources increased significantly also in Krotoszyn Stary deposit – by 0.619 million m3. There were also recalculations of resources made for Pogolewo Duże deposit in Dolnośląskie Voivodeship (+0.618 million m3), Przygodzice (pole II I ob.Wysocko) deposit in Wielkopolskie Voivodeship (+0.148 million m3) and Gliwice zakł.nr 3 deposit in Śląskie Voivodeshi (-0.196 million m3).
The resources decreased also due to the exploitation and loesses (-2.065 million m3).
Out of the total anticipated economic resources 19.4 % are resources within exploited deposits, 71.7 % are resources within non-exploited deposits and 15.2 % are resources within abandoned deposits.
Out of 1,201 documented deposits of building ceramics clays, 19.4 % of deposits are exploited (including 11.2 % deposits exploited continuously and 8.2 % - exploited temporarily) and 25.8 % deposits are non-exploited (including 19.7 % deposits covered by detailed exploration and 6.1 % - covered by preliminary exploration). The remaining deposits were abandoned (54.8 %).
Economic resources within 131 deposits amounted to 165.21 million m3 (about 330.42 million tonnes) and increased by 7.59 million m3 (4.8 %) in comparison with the previous year.
In 2014, production of building ceramics clays was equal 1.953 million m3 (about 3.906 million tonnes). It means significant increase (by 0.435 million m3 – 28.7 %) in comparison with the previous year. Traditionally, the biggest production is observed in the southern Poland – Dolnośląskie Voivodeship (0.302 million m3 – 15.5 % of domestic production), Świętokrzyskie Voivodeship (0.269 million m3 – 13.8 % of domestic production), Śląskie Voivodeship (0.230 million m3 – 11.8 % of domestic production), Mazowieckie Voivodeship (0.201 million m3 – 10.3 % of domestic production), Małopolskie Voivodeship (0.192 million m3 – 9.9 % of domestic production) and Podkarpackie Voivodeship (0.187 million m3 – 9.6 % of domestic production). The production from these 6 Voivodeships accounts for 70.8 % of domestic production. The only Voivodeship without production (since 2012) is Zachodniopomorskie voivodeship.
There were also 5 changes of deposit names – Pawice I i II (former: Pawice) in Dolnośląskie voivodeship, Silesia B (former: Silesia) and Pawłów (former: Pawłow) in Śląskie Voivodeship, Kolosy (former: Kolosy 1) in Świętokrzyskie Voivodeship, Przygodzice (pole II I ob.Wysocko) (former: Przygodzice (ob.Wysocko)) in Wielkopolskie Voivodeship, Polanów (former: Polanów I) in Zachodniopomorskie Voivodeship.
The figure given below shows changes in domestic resources and production of clay raw material for building ceramics industry in Poland in the years 1989-2014.
Prepared by: Wojciech Szczygielski
Table 1. Building ceramics raw material - million m3