Assessment of NORM in bauxite residue to facilitate valorization Andrei Goronovski, Alan Tkaczyk Bauxite Residue Valorisation and Best Practices Conference BR2018

1.Natural radiation Natural radiation is caused mainly by three primordial isotopes (and their decay products): 232Th 238U 40K Bauxite Residue Valorisation and Best Practices Conference BR2018

2.Radionuclides in Greek BR Greek BR Chemical and Radiological Composition: Compound Typically % Fe2O3 42.58 Al2O3 16.63 CaO 11.36 SiO2 7.6 TiO2 5 Na2O 3.49 Rest ~13.34 Isotope Bq/kg 228Ra 435±11 228Th 425±21 238U 151±9 226Ra 174±2 40K 22±6 Lower than in human body, order of magnitude lower of magnitude lower than in the soil. EURATOM Basic Safety Standard: materials with radionuclide concentrations 1 kBq/kg for thorium and uranium series nuclides and 10 kBq/kg for 40K are exempt from further radiological clearance*. *European Parliament, “Council Directive 2013/59/Euratom of 5 December 2013 laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation, and repealing Directives 89/618/Euratom, 90/641/Euratom, 96/29/Euratom, 97/43/Euratom a,” Off J Eur Commun L13, no. December 2003, pp. 1–73, 2014.

3.Result Summary RS- iron recovery with Reductive Smelting. Lower than in human body, order of magnitude lower of magnitude lower than in the soil. RS- iron recovery with Reductive Smelting. RR1- iron recovery with Reductive Roasting and magnetic separation. RR2- iron recovery with Reductive Roasting and magnetic separation. RRNM- non-magnetic fraction (residue) after Reductive Roasting. AL- aluminum recovery with Alkaline Leaching (with Na2CO3). IL- Primary metals and REE recovery with Ionic liquid Leaching. AcL- REE recovery with Acidic Leaching. HNO3, HCL, H2SO4 were used.

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