Foundry sands (SiO2 content >96%) with a low content of alcalic pollutants which are characterize by a high sintering temperature, are the basic raw material for preparing moulds and cores masses (up to 90% of these masses) used in steel castings, iron castings and castings made of metals alloys. For making the steel castings the sands have to be characterized by the sintering temperature of 1,400°C, for the iron castings – 1,350°C, and for the non-ferrous metals castings - 1,200°C. Two types of foundry sands are differentiated on the basis of the cement and carbonates content: pure quartz sands and natural binder (cement) foundry sands. The raw material coming from some of foundry sands deposits can also be used in other applications. Pure quartz sands are used as glass sands or sometimes as sands for building and road industries.
Deposits of Polish foundry sands are situated mainly in the central and southern parts of the country and usually have the form of sand sheet deposits (map). The sand deposits are of the Quaternary, Miocene, Cretaceous and even Jurassic and Triassic age. In the vicinities of Częstochowa, foundry sands of a natural binder occur in infills of the karst forms developed in Upper Jurassic limestones, forming small natural sand deposits of a varying thickness. Foundry sand deposits located in the area between Gorzów Śląski and Żarki are represented by fine- to medium-grained sands and sandstones of the Lower Jurassic age. In turn, weakly cemented sandstones or locally loose sands of the Middle Jurassic age form foundry sand deposits found in the vicinities of Szydłowiec, Wąchock, Skarżysko-Kamienna and Jagodna as well as Opoczno and Iłża. Cretaceous sands are known mainly from the Tomaszów Basin (where they co-occur with those of glass sands) as well as from the Bolesławiec Basin and the vicinities of Krzeszówek in the Lower Silesian region. Tertiary foundry sands represented by deposits of a land environments origin occur in the Konin area, at the margin of the Holy Cross Mts. and in Pomerania, and those of a marine origin occur in the Lublin Upland. In northern Poland mainly the Quaternary age sands occur – these are sediments of dune fields or fluvioglacial terrace accumulations. The prognostic resources of foundry sands are assessed of being equal 289.56 million tonnes as of 31.12.2018, including 37.44 million tonnes within the area of Opolskie Voivodeship and 252.12 million tonnes within the area of Śląskie Voivodeship*.
Anticipated economic resources of foundry sands decreased due to the output and losses by 1.21 million tonnes and amounted to 300.63 million tonnes in 2019. Anticipated economic resources of exploited deposits are covered by the detailed exploration (categories A, B and C1) and are equal 48.39 million tonnes accounting for 16.1% of total anticipated economic resources.
Anticipated economic resources of exploited deposits are covered by the detailed exploration (categories A, B and C1) and are equal 49.60 million tonnes accounting for 16.4% of total anticipated economic resources.
Table 1 shows resources and the state of development and exploration of foundry sands in Poland.
Economic resources of foundry sands decreased by 1.05 million tonnes (it means by 4.71%) in comparison with 2018 due to the exploitation, losses and the elaboration of a new deposit development plan for Zawisna II deposit. There was also a new deposit development plan carried out for Szczakowa deposit which resulted in the economic resources growth despite the ongoing exploitation.
The output of foundry sands in Poland amounted to 1,258.54 thousand tonnes in 2019 and increased by 212.42 thousand tonnes (20.3%) in comparison with the previous year. It was the second consecutive year of the output growth after three previous consecutive years of its declining. The production volume grew from: Szczakowa deposit (by 169.81 thousand tonnes), Grudzeń-Las deposit (by 53.59 thousand tonnes), Ludwików Pole B-1 deposit (by 3.03 thousand tonnes). Moreover, the exploitation from Zawisna deposit was restarted (11.44 thousand tonnes). Again, the output from Ludwików – Pole B deposit was on hold.
The figure given below shows changes in domestic resources and production of foundry sands in Poland in the years 1989-2019.
Prepared by: Agnieszka Malon
* Galos K., Lewicka E., 2020 - Piaski formierskie (foundry sands), piaski dla odlewnictwa (moulding sands). In: Bilans perspektywicznych zasobów kopalin Polski wg stanu na 31.12.2018 r. (eds. Szamałek K., Szuflicki M., Mizerski W.): 321-324. PIG-PIB, Warszawa.