To the group of mineral raw materials for engineering works there have been deposits often called as “earth masses for building purposes” classified. They are usually clastic rocks of a clayey-sandy characteristic e.g.: silty sands, loamy-clayey sediments and mantle rocks, and solid rocks: sandstones, limestones, conglomerates, allocated from the deposits as not fulfilling the criteria necessary for the crushed aggregates production. These raw materials are utilized in the road industry for the road embankments building and the maintenance of dirt roads surfaces. The loamy-clayey raw material can be used for the packing and reclamation of waste disposals, for hydro-building and other purposes. The usefulness of these raw materials is determined by i.e. their geological-engineering parameters, sealing (isolating) properties and others. Usually, the mineral raw materials for engineering works are documented as an accompanying raw material in sand deposits or deposits of the solid rock materials, covering their worse, defective parts. Only in about 30% of cases are documented as the main raw material.
Resources and output
The total anticipated economic resources amount to 17.256 million m3. In comparison with 2019 they increased by 5.488 million m3 (it means by 46.6%).
In 2020, there was only 1 new deposit documented: Dankowice in Dolnośląskie Voivodeship. Clays (0.179 million m3), “used for the sealing of the permeable grounds for the objects connected with the environmental protection”, are the accompanying raw material to the natural aggregates beds.
There were also 5 new documentations with recalculated resources approved for the exploited natural aggregates and dimension and crushed stones deposits, in which the resources of the accompanying raw material were taken into account – mainly the rocks used for the road embankment building. These are: Wereszcze Duże (0.042 million m3) in Lubelskie Voivodeship, Racibórz II – Zbiornik 7 (0.159 million m3) in Śląskie Voivodeship, Danowo (1.618 million m3) and Kołacz (0.042 million m3) in Zachodniopomorskie Voivodeship, and Devonian limestones deposit Kostomłoty (3.663 million m3 – marls, marly schists and marly greenstones) in Świętokrzyskie Voivodeship.
The table given below shows the current state of identification and management of mineral raw materials for engineering works resources in Poland.
The output of mineral raw materials for engineering works amounted to 0.243 million m3 in 2020 decreasing by 0.053 million3 (18%) in comparison with the previous year. There were 13 deposits under exploitation.
The economic resources were calculated for 13 deposits. They amount to 6.364 million m3 in total which accounts for 83% of the anticipated economic and the sub-economic resources of these deposits. These resources increased by 1.560 million m3 (32%) in comparison with 2019.
The figure given below shows changes in domestic resources and production of mineral raw materials for engineering works in Poland in the years 2000-2020.