Thermodynamic study of ferruginous concretions of the western Moa deposit for steel usage

Ferruginous concretions or lateritic debris are environmental liabilities of the nickel industry in Moa. This article states the thermodynamic study of samples concretions of Moa occidental deposit (Zone A), used in decarbonizing ACI HK40 steel produced in an electric arc furnace. The samples of granulometric fractions were characterized by using fluorescence X-ray techniques and X-ray diffraction. The results reveal the existence of mineralogical iron phases such as maghemite and goethite, in correspondence to contents of iron oxide (III). The thermodynamic study focused on the reactions that can occur in the metallic bath when the material is added to the furnace. It was predicted that between the 1 573 K and 1 973 K the decarburization reaction is not possible with the silicon, manganese and aluminum oxides contained in the debris, which become part of the slag; while iron oxide (II), works as an oxidant of carbon and other impurities on the molten metal bath. The experimental tests were developed at industrial scale and thermodynamic study forecasts were corroborated and the possibility of using particles larger than 2 mm as oxidants during the decarburization stage of ACI HK-40 steel, without affecting the chemical composition required for the alloy