Limestones and marls for cement and lime industries
This section deals with deposits of limestones and marls exploited for use in lime or cement industries. Hard varieties of limestone used in the production of dimension and crushed stones are discussed in a separate section, similarly as lacustrine limestone (lacustrine chalk) and proper chalk used in industries other than the cement and lime ones.
Limestones used as a raw material in the lime industry are pure limestones with high content of CaCO3 (>90%). Some types of limestones – meeting additional (mainly chemical) criteria – are also used in chemical, iron and steel and sugar industries, for production of lime powder including sorbents for flue gas desulphurization. When used as so called "high raw material" (incomplete) in a manufacture of a cement clinker, they should be supplemented with addition of clay raw materials. Marly limestones and marls are useful only in the cement industry. In this case, the CaCO3 content can be much lower (below 80%) but other chemical ingredients contents and their percentages ratio are quite important.
Cement and lime raw materials occur quite common in various geological formations, mainly in southern and central Poland. Almost 60% of documented resources are of Jurrasic age. Quite important are also Devonian, Triassic and Cretaceous limestones, whereas Precambrian, Cambrian, Carboniferous and Neogene are of a minor importance. Majority of resources occur within four regions: świętokrzyski, krakowsko-częstochowsko-wieluński, lubelski and opolski. In northern Poland Jurassic limestones were documented within the Barcin-Piechcin area near Inowrocław.
Anticipated economic resources of limestones and marls amounted in 2016 to 18,332.74 million tonnes including 12,806.09 million tonnes (69.9%) within 70 deposits documented for cement industry and 5,526.65 million tonnes (30.1%) within 118 deposits for lime industry.
In 2016, the anticipated economic resources of limestones and marls for cement industry decreased by 26.78 million tonnes in comparison with the previous year. The number of deposits has not changed since 2015. The negative balance was the result of:
increases due to:
- the current verification and recalculation of deposits resources (about 0.22 million tonnes);
decreases due to:
- the exploitation carried out in 18 mines (24.85 million tonnes);
- the current verification or resources adjustment, better exploration of deposits and loesses settlement (about 2.15 million tonnes).
In 2016 the anticipated economic resources of limestones for lime industry decreased by 38.17 million tonnes. The main factors affecting it were:
- the output from 18 active mines (-17.46 million tonnes);
- the crossing out 2 deposits from “The balance…”: Ostrówka and Ołowianka – total decrease equal 251.98 million tonnes;
- the better exploration of deposits, reclassification and recalculation of resources and the losses settlement – the drop equal about 0.52 million tonnes;
- the updating of resources for limestones deposit Trzuskawica as a result of a deposit piece depleting – the drop equal about 14.88 million tonnes;
- the documentation of 2 new limestones deposits: Ostrówka and Sudół – the resources increase by 218.84 million tonnes;
- the extension of boundaries and resources updating for Ołowianka 1 deposit – the increase by 27.76 million tonnes;
- the verification of resources and better exploration of deposits – the growth by about 0.07 million tonnes.
Limestones and marls for cement industry deposits are presented on the map.
The anticipated economic resources of exploited deposits (deposits of operating mines and deposits exploited temporarily) states for 33.6% of total resources documented for cement industry and 32.2% of total resources for lime industry.
The mining of discussed raw materials is concentrated in the area of three voivodeships: - Świętokrzyskie which accounts for 46.6% of domestic production of limestones and marls for cement and lime industries, Opolskie with the share of 18.6% and Kujawsko-Pomorskie (15.3%). The production of both raw materials amounted in 2016 to 42.31 million tonnes and decreased by 0.79 million tonnes in comparison with the previous year. It was mainly the result of production drop for limestones for lime industry (by 1.19 million tonnes), whereas the production of raw material for cement industry increased by 0.40 million tonnes. The most significant drop of limestones and marls for lime industry production was recorded in Łódzkie (by 48%), Małopolskie (9%), Opolskie (6%) and Świętokrzyskie (6%) Voivodeships. In the case of limestones and marls for cement industry, the significant output growth was observed in Dolnośląskie (by 62%) and Śląskie (13%) Voivodeships. The minor drops were recorded for Lubelskie (by 6%) and Opolskie (4%) Voivodeships. Other voivodeships were characterized by 3-5% output increases.
Table 1 shows resources and the current state of exploration and development of limestone and marl deposits explored for the needs of cement industry and table 2 for lime industry.
The figure given below shows changes in resources and production of limestones and marls for the cement and lime industries in Poland in the years 1989-2016.
In a couple of deposits (Bratkowszczyzna, Bukowa, Gliniany-Stróża, Górażdże, Kodrąb-Dmenin, Krasocin, Strzelce Opolskie I and Tarnów Opolski-Wschód) both types of raw material occur.
Prepared by: Dariusz Brzeziński