MagWasteVal Project—Towards Sustainability of Mining Waste

Abstract

In the direction of sustainable mining solid waste management and eventually zero-waste production, the MagWasteVal research program aimed to achieve the proper handling of massive quantities of extractive mining waste originating from the magnesite mines after the enrichment process of useful ore. The main objectives of this project were both the investigation of geochemical variables affecting the serpentinization process (degradation) and the respected exploitation and further valorization of stocked-pilled solid (inert) wastes in the mining area. The study of thermal treatment (considering the heating duration and heating temperature) and the addition of various additives (alumina, chromite ore, run of mine, iron oxide, and magnesia) showed that the optimum upgrade for the mining waste samples occurs when a combination of magnesia (according to the optimum defined molar ratio: [MgO] + [FeO])/[SiO2] = 2) and iron oxide of approximately 2.5% is applied at both 1300 and 1600 °C for 120 min. The final products of the MagWasteVal project may have various potential applications, even on a large scale, for the production of alternative refractory materials/services, substituting other raw materials, and presenting both economic and environmental benefits.