Building ceramics raw materials
The basic raw materials used for a building ceramics production are various clayey rocks which mixed with water form a plastic mass easy to form and sands so-called “weaken sands” which are added to a clayey raw material to improve the properties of the ceramic mass. The formed and burnt products must be of the appropriate physical and technical features defined by the official standards. Clayey and non-clayey (weaken) raw materials often occur together - in one deposit, in the form of beds or interbeddings, or as the independent accumulations.
The main building ceramic products are: ceramic bricks and breezeblocks, slates, clinker bricks, fittings, ceramic pavements. The raw material from some deposits is being used also for the production of enamel ceramic tiles, stoneware products, ceramic accessories and others.
The raw materials for the building ceramics production owe their yielding features and their ability to be formed to the clayey minerals content. Their content in different rocks varies. In loesses the clayey minerals content is low (couple of %), but in clays it can be up to 100%. Usually in the typical raw materials the content is between 40% and 60%. Other components are mainly the quartzitic sand and dust, feldspars, calcite and dolomite in calcareous raw materials, iron minerals, mica minerals and organic matter. Clayey rocks built of only one mineral occur very seldom, they mostly have several clayey minerals in their composition: kaolin, illite, montmorillonite and chlorites, occurring together in changeable proportions.
Building ceramics raw materials occur commonly in the whole country. They vary in terms of their origin and age. Nowadays, the most important raw materials are these of the Quaternary, Neogene, Jurassic and Triassic age. The raw materials of the Quaternary age include mainly stagnant lake sediments such as muds and clays occurring mainly in northern and central Poland. There are also loesses, glacial loams, alluvial loams and loams of weathering covers nad 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., in the Czestochowa region and in the Opole region. 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 regarding the geological documentation of a mineral raw material deposit, excluding a hydrocarbons field (number of Polish act: Dz. U. 2015, poz. 987) the limit values of the parameters that define the building ceramics raw materials deposit and its borders (Appendix 8 – table 42) are: - the maximum documentation depth – to the depth of a 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 a ceramic marl in 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 of building ceramics raw materials amounted to 2,044.252 million m3 (about 4,088.504 million tonnes) as of the end of 2018. They increased by 13.372 million m3 (about 26.744 million tonnes – 0.7%) in comparison with the previous year.
There were 3 newly documented deposits included in “The balance…”: Sośnica 1 (0.307 million m3) located in Dolnośląskie Voivodeship – the deposit was allocated from Sośnica deposit, Rojów II (0.033 million3) located in Wielkopolskie Voivodeship and Gnaszyn – Północ located in Śląskie Voivodeship (4.462 million m3).
In 2018 there were 27 new documentations with recalculated resources approved. Most of them were elaborated in the result of the exploitation end or the expiry date of the concession, in order to the resources settlement (21 documentations). Other documentations are related to: the enlargement of a deposit area (3), the enlargement of a deposit area and a change of the raw material usage (1), the updating of resources in the result of a deposit division (1), the updating of resources according to new balancing criteria (1).
The significant resources growths were recorded in the deposits for which the border have been enlarged: Kolbuszowa-Kupno (12.286 million m3) located in Podkarpackie Voivodeship and Sierakowice (1.770 million m3) located in Śląskie Voivodeship. The important increases were also the result of the resources updating of Lajsy deposit (0.228 million m3) located in Warmińsko-Mazurskie Voivodeship, Pieńkowo II deposit (0.020 million m3) located in Zachodniopomorskie Voivodeship and Bojanice deposit (0.011 million m3) located in Wielkopolskie Voivodeship.
The biggest resources drops occurred in the following deposits: Buśno (0.976 million m3) – the raw material was reclassified into the chapter Clay raw materials for cement production, Gozdnica (0.819 million m3) – in the result of the resources updating according to the current parameters that define the deposit and its borders, Sośnica (0.523 million m3) after the allocation of Sośnica 1 deposit, Lipie Śląskie – Lisowice (0.109 million m3) and Głogówek (0.025 million m3).
There were 14 deposits crossed out from “The balance…”: Wola Bachorska I (0.047 million m3) located in Łódzkie Voivodeship; Gaboń-Grabie (0.085 million m3), Hebdów (0.508 million m3), Stróże (0.030 million m3) located in Małopolskie Voivodeship; Drwały (0.004 million m3), Guzowatka III (0.077 million m3), Kobyłka Kolonia Chór 5 (0.033 million m3), Małopole III (0.050 million m3), Mokre IV (0.125 million m3), Mokre – Truszkowski, Kryski (0.106 million m3) located in Mazowieckie Voivodeship; Wrzawy – Laskowski I (0 million m3) located in Podkarpackie Voivodeship; Wyszyna Fałkowska I (0.163 million m3), Wyszyna Fałkowska II (0.000 million m3 – in the deposit there were only anticipated sub-economic resources documented and exploited) located in Świętokrzyskie Voivodeship; Guzy III (0.000 million m3) located in Warmińsko-Mazurskie Voivodeship. The total resources drop resulted from crossing out the above mentioned deposits was equal 1.228 million m3.
The resources of Buśno deposit (0.976 million m3 – the building ceramics raw material) were reclassified into the chapter Clay raw materials for cement production due to the change of the raw material usage. From the loessal loams of this deposit the ceramic brick was being produced from ‘60s of the 20th century till 2012. Then, this type of production was abandoned and the raw material started to being used for the production of the cement clinker in the Chełm cement plant. The reclassification – the change of the raw material type – was based on the new documentation with recalculated resources elaborated for loessal loams deposit Buśno, intended for the cement production. The documentation was approved in 2018 and resulted in the resources updating and the extension of the previous deposits borders.
Out of 1,148 documented deposits of building ceramics raw materials, exploited deposits account for 13.4% (including: 8.8% deposits exploited continuously and 4.6% deposits exploited temporarily), non-exploited deposits account for 26.7% (including: 20.2% deposits covered by a detailed exploration and 6.4% deposits covered by a preliminary exploration) and abandoned deposits account for 59.9%.The number of abandoned deposits – reported in the domestic records – has been increasing systematically for many years.
Out of the total amount of the anticipated economic resources, the resources within exploited deposits account for 12.4% (including: 10.8% deposits exploited continuously and 1.6% deposits exploited temporarily), the resources within non-exploited deposits account for 71.0% (including: 11.4% in the deposits covered by a detailed exploration and 59.6% in the deposits covered by a preliminary exploration) and the resources within abandoned deposits account for 16.6%.
Resources documented in A+B and C1 categories (the detailed exploration) account for 34.7% of total anticipated economic resources. The remaining part of resources is documented in C2 or D categories (the preliminary exploration). More than a half of resources covered by the preliminary exploration (54.5%) are resources documented within the overburden of non-exploited brown coal deposit Legnica-pole Wschodnie (727.65 million m3 of clays documented in C2 category).
Economic resources were documented for 74 deposits and amounted to 136.280 million m3 (about 272.560 million tonnes) that accounts for 52.5% of anticipated economic resources of these deposits. The economic resources decreased by 4.533 million m3 (3.2%) in comparison with the previous year mainly as a result of the crossing out the economic resources from “The balance…” for these deposits for which the exploitation concessions extinct.
In 2018, the output of building ceramics clays was equal 2.042 million m3 (about 4.084 million tonnes) and increased in comparison with 2017 by 0.498 million m3 (32.3%). It was the highest output level in the last few years: in the 2012-2017 period, the exploitation remained in the range between 1.518-1.950 million m3, 1.915 million m3 at the average.
In terms of a genetic origin, the output is as follows: the Neogene clays of the so-called Poznań Series 0.668 million m3 (accounting for 32.7% of the total output), the Miocene clays of the Carpathian Foredeep 0.584 million m3 (28.6%), the Quaternary stagnant lake clays 0.329 million m3 (16.1%), the Triassic clays 0.194 million m3 (9.5%), the Jurassic clays 0.193 million m3 (9.5%), other clays in total 0.073 million m3 (3.6%).
Considering particular Voivodeships, the output was as follows (in a descending sequence): in Świętokrzyskie Voivodeship 0.372 million m3 (18.2% of the domestic output), in Dolnośląskie Voivodeship 0.276 million m3 (13.5%), in Pomorskie Voivodeship 0.229 million m3 (11.2%); in Śląskie Voivodeship 0.209 million m3 (10.2%); in Małopolskie Voivodeship 0.188 million m3 (9.2%); in Opolskie Voivodeship 0.160 million m3 (7.9%); in Podkarpackie Voivodeship 0.158 million m3 (7.7%); in Mazowieckie Voivodeship 0.131 million m3 (6.4%); in Wielkopolskie Voivodeship 0.102 million m3 (5.0%); in Lubelskie Voivodeship 0.062 million m3 (3.0%); in Lubuskie Voivodeship 0.043 million m3 (2.1%); in Łódzkie Voivodeship 0.031 million m3 (1.5%); in Podlaskie Voivodeship 0.030 million m3 (1.5%); in Kujawsko-Pomorskie Voivodeship 0.024 million m3 (1.2%); in Zachodniopomorskie Voivodeship 0.020 million m3 (1.0%) and in Warmińsko-Mazurskie Voivodeship 0.007 million m3 (0.3%).
The figure given below shows changes in the domestic resources and production of the clay raw material for the building ceramics industry in Poland in the years 1989-2018.
Prepared by: Wojciech Szczygielski
Table 1. Building ceramics raw material - million m3