Investigation of Magnetic Separation and Thermal Treatment Effects, Combined with Additives (Mineral Oxides), on Serpentinized Peridotites from the Gerakini (Chalkidiki, N. Greece) Magnesite Mine

Abstract

Serpentinized peridotite samples—considered nowadays as deposited waste at the magnesite mine of Gerakini (Chalkidiki, N. Greece)—were collected, and their chemical and mineralogical characterization analyzed with Energy-Dispersive X-ray Fluorescence (ED-XRF) and X-ray Diffractometry (XRD). Dry magnetic separation was used as a convenient enrichment method; however, no significant effect was shown in the chemical composition of separated (magnetic and non-magnetic) fractions, except for small increases in the olivine, antigorite and enstatite contents, which were observed in the non-magnetic fraction. Finally, the calcination of ground peridotites at 1520 ◦C, with the addition of CaO, Al2O3 and SiO2, presented a negative effect on the structure of the products with regard to their main refractory properties. In contrast, the addition of Cr2O3 and MgO mineral oxides showed improved refractory properties when compared with the initial material.