Foundry sands are the basic raw material for making moulds and cores used in metal casting. The sands have to be characterized by high sintering temperatures as the sintering temperature required for making cast steel is 1,400°C, for cast iron – 1,350°C, and for non-ferrous casting alloys - 1,200°C. Two kinds of foundry sands are differentiated on the basis of content of cement and carbonates: pure quartz sands and natural foundry sands. Deposits of foundry sands are situated mainly in central and southern parts of Poland and usually have the form of sand sheet deposits. The sand deposits range in age from the Quaternary and Tertiary to Cretaceous and even Jurassic and Triassic.
In the vicinities of Częstochowa (map), small natural foundry sand deposits of varying thickness represent infills of karst forms developed in Upper Jurassic limestones. Foundry sand deposits from 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 deposits of foundry sands are known mainly from the Tomaszów Basin (central Poland) where they cooccur with those of glass sands as well as from the Bolesławiec Basin and vicinities of Krzeszówek in the Lower Silesian region. Foundry sand deposits formed of Tertiary sands deposited in land environments occur in the Konin area, at the margin of the Holy Cross Mts and in Pomerania, and those formed of Tertiary sands of marine origin – in the Lublin Upland. Foundry sand deposits of the Quaternary age occur in the northern Poland and are formed of sands of dune fields or fluvioglacial terrace accumulations.
Raw material from some deposits of foundry sands may also find other uses. Pure quartz sands are used also in glass industry and sometimes in construction and road building.
Anticipated economic resources amounted to 294.54 million tonnes in 2013 and decreased by 19.75 million tonnes in comparison with the previous year. There was one deposit crossed out of “The balance…” – Sulechowo (with resources equal 4.45 million tonnes). The raw material from Czerwona Woda deposit was reclassified as sands and the deposit is presented in the “Sand and gravel” chapter.
Anticipated economic resources of exploited deposits are equal 40 million tonnes accounting for 13.6 % of total anticipated economic resources. These resources decreased by 23.77 million tonnes mainly due to the end of Krzeszówek deposit exploitation (-8.9 million tonnes).
The table below shows resources and the state of development and exploration of foundry sands in Poland.
Economic resources decreased by 14.25 million tonnes in comparison with 2012 mainly through the end of Krzeszówek deposit exploitation and reclassification of raw material from Czerwona Woda deposit.
In 2013 production of foundry sands was equal 1.311 million tonnes – increased by 105 thousand tonnes.
The figure given below shows changes in domestic resources and production of foundry sands in Poland in the years 1989-2013.
Prepared by: Agnieszka Malon