Building ceramics raw materials
Main raw materials used for a building ceramics production are various clay 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. Formed and burnt products must be of the appropriate physical and technical features defined by the official standards. Clay and non-clay (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, ceramic pavements. The raw material from some deposits is being used for the production of ceramic tiles, stoneware products, ceramic accessories and others.
Raw materials for the building ceramics production contain clayey minerals. Their content in different rocks varies. In loesses the clayey minerals content is low (couple of %), but in clays it can be 100%. Usually the content is between 40% and 60%. Other components are mainly quartz 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 are 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 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. 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 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 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 of building ceramics raw material amounted to 2,030.880 million m3 in 2017 (about 4,061.760 million tonnes) and decreased by 1.802 million m3 (about 3.604 million tonnes – 0.1%) in comparison with the previous year.
There were 4 new deposits documented in 2017: Bukówek in Dolnośląskie Voivodeship with anticipated economic resources equal 2.099 million m3, Markowicze I in Lubelskie Voivodeship with resources equal 5.510 million m3, Trześń-Łabuda IV in Podkarpackie Voivodeship with resources equal 0.031 million m3 and Witaszyce 1 in Wielkopolskie Voivodeship with resources equal 0.306 million m3. The latest one was allocated from Witaszyce deposit.
There were 22 new documentations with recalculated resources approved in 2017.
There were 11 deposits crossed out from “The balance…” of which for 10 deposits there were new documentations with resources settlement approved and only Racibórz 1 i 2 deposit was crossed out due to the verification of documents issued in 1997. In Dolnośląskie Voivodeship there was 1 deposit crossed out: Ścinawka Średnia – the resources drop equal 1.759 million m3; in Lubuskie Voivodeship 1 deposit: Budych I – the resources drop equal 3.414 million m3; in Małopolskie Voivodeship 1 deposit: Wadowice-Łazówka – the resources drop equal 0.335 million m3; in Mazowieckie Voivodeship 3 deposits: Ciemne VI, Marki – Lisa Kuli 69 and Nowe Słupno V – the total resources drop equal 0.122 million m3; in Podkarpackie Voivodeship 1 deposit: Wrzawy – Woźniak III – the resources drop equal 0.003 million m3; in Śląskie Voivodeship 2 deposits: Racibórz and Racibórz 1 i 2 – the total resources drop equal 0.085 million m3; in Świętokrzyskie Voivodeship 1 deposit: Wyszyna Machorowska II – the resources drop equal 0.046 million m3; in Wielkopolskie Voivodeship 1 deposit: Wysoka – the resources drop equal 0.026 million m3. The anticipated economic resources of the deposits mentioned above amounted to 5.789 million m3.
Pęglity deposit, located in Warmińsko-Mazurskie Voivodeship, was moved to the chapter Sand and gravel with anticipated economic resources of the deposit equal 0.353 million m3. The sands documented in this deposit meet the criteria for building sands but were exploited and used as a weaken raw material for the building ceramic production by a nearby ceramic factory. Therefore, the deposit was classified as a building ceramics raw material. Nowadays, due to the exploitation abandonment and the brick factory liquidation, the raw material qualification has changed.
Out of the total anticipated economic resources 12.3% are resources within exploited deposits, 71.3% resources within non-exploited deposits (from that 11.6% within deposits covered by a detailed exploration and 59.7% within deposits covered by a preliminary exploration) and 16.4% resources within abandoned deposits.
Out of 1,157 documented deposits of building ceramics clays 15.5% are exploited deposits (including 8.3% deposits exploited continuously and 7.2% - exploited temporarily), 26.5% non-exploited deposits (including 20.1% deposits covered by a detailed exploration and 6.4% - covered by a preliminary exploration) and 58.0% abandoned deposits.
Resources documented in A+B and C1 categories (the detailed exploration) account for 34.5% 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 (54.7%) 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 within 85 deposits and amounted to 140.813 million m3 (about 281.626 million tonnes) that accounts for 55.0% of anticipated economic resources of these deposits. The resources decreased by 13.404 million m3 (8.7%) in comparison with the previous year mainly as a result of the extinction of the abandoned deposits exploitation concessions.
In 2017, the output of building ceramics clays was equal 1.544 million m3 (about 3.088 million tonnes). It means that the production decreased by 0.038 million m3 (2.4%) in comparison with the previous year. The output of building ceramics raw materials is characterized by a declining tendency over the recent years and the amount recorded in 2017 was the lowest one over the several dozen years. Moreover, the part of the given output was used for other purposes than the production of building ceramics: 0.058 million m3 of clay and clay slate from Biecz 1 deposit was used for the flood banks building and 0.029 million m3 of loess raw material from Buśno deposit was used for the cement clinker kiln.
The low level of the output and the growing intensity of the searching of the alternative building raw materials uses are the result of the changes in the ceramic industry and the market. The liquidation of the consecutive ceramic factors is caused by: - the domination of the large-sized products; - the lower raw material consumption per a ceramic unit; - the growing competition of other building materials; - the progress of the building technology together with the low production profitability and the difficulties with the products sales. These factors determine the problems for factories in coping with the current economy conditions. Moreover, these factors cause also the loss of the deposits value as ceramic raw materials or as mineral in general, because they cannot be used for any other purpose. Such a situation is a base for the geological administration authorities to initiate the procedure of crossing the deposit and its non-exploited resources out from the national registry to make the areas enable for other purposes.
Considering particular voivodeships, the output was as follows (in a descending sequence): in Świętokrzyskie Voivodeship 0.250 million m3 (16.2% of the domestic output); in Małopolskie Voivodeship 0.193 million m3 (12.5%); in Dolnośląskie Voivodeship 0.173 million m3 (11.2%); in Podkarpackie Voivodeship 0.155 million m3 (10.1%); in Mazowieckie Voivodeship 0.150 million m3 (9.7%); in Śląskie Voivodeship 0.149 million m3 (9.7%); in Opolskie Voivodeship 0.095 million m3 (6.2%); in Pomorskie Voivodeship 0.092 million m3 (6.0%); in Wielkopolskie Voivodeship 0.081 million m3 (5.3%); in Lubelskie Voivodeship 0.079 million m3 (5.1%); in Lubuskie Voivodeship 0.046 million m3 (3.0%); in Łódzkie Voivodeship 0.040 million m3 (2.6%); in Kujawsko-Pomorskie Voivodeship 0.019 million m3 (1.3%); in Podlaskie Voivodeship 0.010 million m3 (0.6%); in Warmińsko-Mazurskie Voivodeship 0.009 million m3 (0.6%) and in Zachodniopomorskie Voivodeship 0 million m3 (0.0%). Zachodniopomorskie Voivodeship is the only one without production (since 2012).
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 1989-2017.
Prepared by: Wojciech Szczygielski