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 2,043.52 million m3 in 2013 (about 4,087.04 million tonnes) and increased by 11.63 million m3 (about 23.26 million tonnes).
There were 4 new deposits documented: Wrzawy – Laskowski VI in Podkarpackie Voivodeship (with resources equal 0.024 million m3), Oleśnica 2, Samsonów – Ciągłe and Wyszyna Machorowska III in Świętokrzyskie Voivodeship (with resources equal 21.553 million m3, 2.963 million m3 and 1.524 million m3 respectively). The total anticipated economic resources growth amounted to 24.539 million m3 and anticipated subeconomic resources to 1.611 million m3.
Due to the new documentation approved there were 20 deposits crossed out of “The balance…”: - Fordon and Papowo in Kujawsko-Pomorskie Voivodeship, Dąbrowa and Sabaudia II – pole B in Lubelskie Voivodeship, Zesławice in Małopolskie voivodeship, Kobyłka Kolonia Chór-dz.46, Marki ul. Szkolna 74 and Zawady 1 in Mazowieckie Voivodeship, Chwałowice – Bałdos, Chwałowice-Maj, Pniów dz.ew. 716/2, Rożniaty-Piątek I, Rożniaty-Piątek II, Trześń-Foltarz II, Wrzawy-Jurek and Wrzawy-Jurek I in Podkarpackie Voivodeship, Karbowa, Miasteczko Śląskie and Pacanów 5 in Śląskie Voivodeship and Kotuń in Wielkopolskie Voivodeship. The total anticipated economic resources drop amounted to 10.597 million m3.
The resources decreased significantly also in Rypinek deposit (Wielkopolskie Voivodeship) – by 1.316 million m3, Rojów deposit (Wielkopolskie Voivodeship) – by 0.106 million m3 and Ruszowice II deposit (Dolnośląskie Voivodeship) – by 0.107 million m3.
The most significant increases of resources were noted for Sierakowice deposit (Śląskie Voivodeship) – by 0.855 million m3, Cienia deposit (Wielkopolskie Voivodeship) – by 0.184 million m3 and Faustianka deposit (Śląskie Voivodeship) – 0.166 million m3.
Out of the total anticipated economic resources 13.1 % are resources within exploited deposits, 71.8 % are resources within non-exploited deposits and 15.1 % are resources within abandoned deposits.
Out of 1,219 documented deposits of building ceramics clays, 20.0 % of deposits are exploited (including 10.5 % deposits exploited continuously and 9.5 % - exploited temporarily) and 25.7 % deposits are non-exploited (including 19.7 % deposits covered by detailed exploration and 6.0 % - covered by preliminary exploration). The remaining deposits were abandoned (54.3 %).
Economic resources within 139 deposits amounted to 157.62 million m3 (about 315.24 million tonnes) and increased by 10.36 million m3 (7.0 %) in comparison with the previous year.
In 2013, production of building ceramics clays was equal 1.518 million m3 (about 3.036 million tonnes). It means significant drop (by 0.317 million m3 – 17.2 %) in comparison with the previous year. Traditionally, the biggest production is observed in the southern Poland – Dolnośląskie Voivodeship (0.228 million m3), Świętokrzyskie Voivodeship (0.195 million m3), Podkarpackie Voivodeship (0.192 million m3), Śląskie Voivodeship (0.170 million m3), Małopolskie Voivodeship (0.140 million m3) and Opolskie Voivodeship (0.117 million m3).
The figure given below shows changes in domestic resources and production of clay raw material for building ceramics industry in Poland in the years 1989-2013.
Prepared by: Wojciech Szczygielski
Table 1. Building ceramics raw material - million m3