Building ceramics raw materials
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.
The main building ceramic products are: ceramic bricks and breezeblocks, slates, clinker bricks, ceramic pavements.
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 Permian to Quaternary. The deposits are distributed practically throughout the whole country. However, they are more common and larger in the southern part and also their differentiation appears higher than in other parts of the country.
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. Clayey rocks are very seldom built of only one mineral, they mostly have several clayey minerals in their composition: kaolin, illite, montmorillonite and chlorites, occurring together in changeable proportions.
Building ceramics raw materials occur in the whole country. They vary in terms of their origin and age. Nowadays, the most important raw materials are these of the Quaternary, Tertiary, Jurassic and Triassic age. Raw materials of Quaternary age include mainly stagnant lake sediments such as muds and clays occurring mainly in northern and central Poland. There are also loesses, glacial tills, alluvial sediments and those of weathering covers and sands used. Among older minerals the most important are Neogene 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 Jurassic and Triassic 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 1st of July 2015 (number of Polish act: Dz. U. 2015, poz. 987) the limit values of the parameters that defines the deposit (Appendix 8 – table 42) 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%.
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 2,032.682 million m3 in 2016 (about 4,065.364 million tonnes) and decreased by 4.587 million m3 (about 9.174 million tonnes – 0.23%).
There were 6 new deposits documented in 2016. 1 deposit in Łódzkie Voivodeship: Michałów VI; 2 deposits in Podkarpackie Voivodeship: Wrzawy Jurek 2 and Zalesie Gorzyckie – Dul 9; 1 deposit in Śląskie Voivodeship: Leśna 1; 1 deposit in Świętokrzyskie Voivodeship: Wyszyna Rudzka; 1 deposit in Zachodniopomorskie Voivodeship: Drawno. Their total anticipated economic resources amounted to 2.605 million m3.
There were 18 deposits crossed out from “The balance…”. In Lubelskie Voivodeship 3 deposits: Stawki, Stawki IV, Wincentów I – with resources equal 0.048 million m3; in Lubuskie Voivodeship 1 deposit: Brzozowiec I – 0.154 million m3; in Łódzkie Voivodeship 1 deposit: Michałów V – 0.003 million m3; in Małopolskie Voivodeship 1 deposit: Wojnarowa I – 0.305 million m3; in Mazowieckie Voivodeship 5 deposits: Kobyłka-dz.59, Kosewo 1, Kosewo 2, Radziejowice (2.772 million m3), Radzymin – zarej. – total resources equal 2.890 million m3; in Podkarpackie Voivodeship 3 deposits: Wrzawy – Woźniak 2, Zalesie Gorzyckie-Kułaga I, Gorzyce-Grzegorzek 1 – total resources equal 0.021 million m3; in Pomorskie Voivodeship 1 deposit: Łapalice – 0.000 million m3 (anticipated economic resources only within protective pillars and anticipated sub-economic resources); in Śląskie Voivodeship 2 deposits: Bogucice and Kawki – total resources equal 0.324 million m3; in Świętokrzyskie Voivodeship 1 deposit: Przełom – 0.049 million m3. Total resources of the deposits mentioned above amounted to 3.793 million m3.
Out of the total anticipated economic resources 13.5% are resources within exploited deposits, 70.9% resources within non-exploited deposits (from that 11.5% within deposits covered by detailed exploration and 59.4% within deposits covered by preliminary exploration) and 15.6% resources within abandoned deposits.
Out of 1,171 documented deposits of building ceramics clays, 17.9% are exploited deposits (including 9.0% deposits exploited continuously and 8.9% - exploited temporarily), 26.2% non-exploited deposits (including 20.0% deposits covered by detailed exploration and 6.2% - covered by preliminary exploration) and 55.9% abandoned deposits.
Resources documented in A+B and C1 categories (detailed exploration) account for 34.9% of total anticipated economic resources. The remaining part of resources is documented in C2 category (preliminary exploration). More than a half of resources in C2 category (54.9%) are resources documented within the overburden of non-exploited brown coal deposit Legnica-pole Wschodnie (727.65 million m3 of clays).
Economic resources within 102 deposits amounted to 154.217 million m3 (about 308.434 million tonnes) that accounts for 55.0% of anticipated economic resources of these deposits. The resources decreased by 2.805 million m3 (1.8%) in comparison with the previous year.
In 2016, production of building ceramics clays was equal 1.582 million m3 (about 3.164 million tonnes). It means that the production slightly decreased (by 0.085 million m3 – 5.1%) in comparison with the previous year. Generally speaking, the output of building ceramics raw materials is characterized by declining tendency over the recent years.
Considering particular voivodeships, the output was as follows (in descending sequence): in Świętokrzyskie Voivodeship 0.249 million m3 (15.7% of domestic output); in Śląskie Voivodeship 0.223 million m3 (14.1%); in Dolnośląskie Voivodeship 0.165 million m3 (10.4%); in Opolskie Voivodeship 0.165 million m3 (10.4%); in Małopolskie Voivodeship 0.153 million m3 (9.7%); in Mazowieckie Voivodeship 0.126 million m3 (8.0%); in Podkarpackie Voivodeship 0.125 million m3 (7.9%); in Pomorskie Voivodeship 0.103 million m3 (6.5%); in Wielkopolskie Voivodeship 0.093 million m3 (5.9%); in Lubelskie Voivodeship 0.067 million m3 (4.2%); in Lubelskie Voivodeship 0.043 million m3 (2.7%); in Łódzkie Voivodeship 0.028 million m3 (1.8%); in Kujawsko-Pomorskie Voivodeship 0.025 million m3 (1.6%); in Warmińsko-Mazurskie Voivodeship 0.009 million m3 (0.6%); in Podlaskie Voivodeship 0.008 million m3 (0.5%). Zachodniopomorskie Voivodeship is the only one without production (since 2012).
There was also 1 change of deposit name – Moszczenica (former name: Moszczenica No 6) in Śląskie Voivodeship – according to the decision approving the documentation.
The figure given below shows changes in domestic resources and production of clay raw material for building ceramics industry in Poland in the years 1989-2016.
Prepared by: Wojciech Szczygielski