General information and occurrence
Backfilling sands are used for making a hydraulically placed fill – a mixture of sand and water to fill depleted mining excavations. Documented backfilling sands deposits occur in the areas of an intensive underground mining, especially those of the hard coal and copper ores in the southern part of Poland, mainly in the Upper Silesian Coal Basin area and in the Lubin vicinities. One of the major requirements which sand deposits should meet to be classified as backfilling sand deposits is the location at the distance less than 50 km from the place where the raw material is to be used.
The majority of backfilling sand deposits is located around the Upper Silesian Coal Basin. Three main deposit areas can be differentiated: eastern, western and northern. The eastern area (where the majority of the raw material volumes is exploited) extends from Kuźnica Warężyńska through the Pustynia Błędowska Desert as far as the vicinities of Jaworzno. It is characterized by the occurrence of sands of fluvioglacial and partially eolian origin, attaining up to 70 m in a thickness (Pustynia Błędowska Desert). The second area with the largest resources covers the proglacial stream valley of the Odra River in a part of the Racibórz Basin and a western part of the Silesian Upland. The average thicknesses of the deposits located within this area are within the range of 15 – 20 m. The northern area covers the Mała Panew River valley where fluvioglacial sand deposits occur, characterized by the significant thicknesses (up to 40 m). The deposits are explored well enough but have not been exploited so far. Moreover, sandy-gravel sediments up to 30 m in thickness occur in the copper mining areas in the vicinities of Lubin. The large number of documented backfilling sands deposits in Poland together with the declining demand are 2 main factors for not delineating the prognostic areas for this raw material at the moment*.
The clastic rock raw materials occurrence in Poland (including backfilling sand) is presented on the map.
Resources and output
The table given below shows resources and the current state of exploration and development of backfilling sand deposits.
In 2020, the anticipated economic resources of backfilling sands slightly increased (by 4.86 million m3) in comparison with the previous year and amounted to 2,510.74 million m3 in 2021 (or about 4,268.26 million tonnes as recalculated using a weight-to-volume ratio 1.7 t/m3). The growth was recorded despite the ongoing exploitation and the crossing out the resources of Hutki II deposit from “The balance…” (Małopolskie Voivodeship; -0.49 million m3), as there was a new documentation with recalculated resources (the supplement No 4) approved for the Obora deposit (Dolnośląskie Voivodeship) – enlarging the deposit area and the deposit resources by 7.86 million m3. There was also a new documentation approved for the Szczakowa-Bukowno deposit (Małopolskie Voivodeship) which has not changed the resources volume but was focused on the raw material quality and the hydrogeological conditions.
The economic resources decreased by 5.36 million m3 in comparison with 2020 due to the exploitation and the extinction of the exploitation concession for the Bór Wschód deposit (Śląskie Voivodeship; -3.28 million m3) and the Hutki II deposit (Małopolskie Voivodeship; -0.20 million m3) and amounted to 42.91 million m3. In 2021, there was a new exploitation concession issued for the Bór Zachód deposit and the economic resources were estimated at 0.55 million m3.
The output of backfilling sands from 6 exploited deposits in 2021 decreased by 62.82 thousand m3 in comparison with the previous year and totaled 2,725.25 thousand m3 (4,632.93 thousand tonnes). The exploitation increased from the Pustynia Błędowska – blok IV deposit (Małopolskie Voivodeship), whereas in the remaining deposits the output remained at the stable level or was lower. The exploitation from the Kuźnica Warężyńska and the Szczakowa pole I deposits is still on hold, however, the Kuźnica Warężyńska deposit is classified as abandoned because the output has not been carried out for more than 10 years.
The figure given below shows changes in domestic resources and production of backfilling sands in Poland in the years 1989-2021.
Prepared by: Agnieszka Malon
* Galos K., Miśkiewicz W., 2020 - "Piaski kwarcowe do produkcji betonów komórkowych (quartz sand for cellular concrete manufacture), piaski kwarcowe do produkcji wyrobów wapienno-piaskowych (quartz sand for lime-sand products manufacture), piaski podsadzkowe (filling sand)". In: "Bilans perspektywicznych zasobów kopalin Polski wg stanu na 31.12.2018 r." (eds. Szamałek K., Szuflicki M., Mizerski W.): 309-313. PIG-PIB, Warszawa [in Polish].