Pregledni rad

https://doi.org/10.4154/gc.2025.04

Croatian Critical Mineral Commodity Letters: Magnesium

Sibila Borojević Šoštarić ; University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering, Zagreb, Croatia
Nenad Tomašić ; University of Zagreb, Faculty of Science, Department of Geology, Zagreb, Croatia
Vječislav Bohanek ; University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering, Zagreb, Croatia
Nikola Gizdavec ; Croatian Geological Survey, Zagreb, Croatia
Slobodan Miko ; Croatian Geological Survey, Zagreb, Croatia

Sažetak

Magnesium is a critical raw material of high importance to the European Union economy. Magnesium has versatile applications in many industries: the automotive industry (48%), packaging applications (23%), the construction industry (13%), desulphurisation of steel (12%), heavy transportation (air, marine, train; 4%) as well as in medical equipment, sport applications, electrochemical and organic chemistry applications. The Republic of Croatia hosts two major sources of magnesium: (1) primary dolostone deposits and occurrences, mainly used as a high-quality crushed stone aggregate and carbonate mineral raw material for industrial processing, and (2) secondary Mg reject brine from the Nin, Pag and Ston saltpans: (1) Deposits and occurrences of early and late diagenetic dolostone are associated with the South Tethyan Megaplatform (STM; Upper Triassic Hauptdolomite and Lower Jurassic limestone and dolostone) or the Adriatic Carbonate Platform (AdCP; Jurassic limestone and dolostone and Upper Jurassic boundstones, layered and massive dolostone and Lower to Middle Cretaceous dolostone and post-sedimentary, diagenetic breccia). Based on their lithological, mineralogical, and chemical characteristics, STM deposits are considered high-potential magnesium sources, whereas AdCP deposits belong to medium-to-high (Jurassic) and low-potential (Cretaceous) magnesium sources. The overall geological potential of primary magnesium sources at a scale of 1:300,000 has been calculated by excluding areas where exploitation is prohibited. In the resulting areas, exploitation is possible, but additional restrictions arising from the three levels of spatial plans (national, county, and local) must additionally be taken into account. (2) Average annual salt production in Croatia is around 20,000 t. The calculated amount of discharged magnesium from highsaline brines remaining after the precipitation of sodium-chloride is about 2.38 t/annually. The case study on the Đipalo dolostone deposit near Sinj (STM dolostone; exploitation reserves of 5.9 Mt) shows high purity dolostone with MgO > 22 wt%, whereas the sum content of SiO2, Fe2O3 and Al2O3 remains below 1 wt%. The Đipalo dolostone can be used in the refractory material industry, as an agent of fusion in ferrous metallurgy, in the production of cement, glass, ceramics, paper or for magnesium metal production. The prices of various Mg-products range from 1.7 €/t construction mineral raw material, 10 €/t for crushed stone aggregate, 100 €/t for refractory (roasted) dolostone and about 2,250 €/t for 99,0% pure magnesium (February 2024). Dolostone consumption for the Đipalo deposit is estimated to be about 10-15 t of dolostone per tonne of Mg metal produced, depending on the process, however, the estimated CO2 emissions remain a significant negative factor.

Ključne riječi

critical raw materials; magnesium; dolostone; Croatia

Hrčak ID:

328783

URI

https://hrcak.srce.hr/328783

Datum izdavanja:

27.2.2025.

Posjeta: 847 *