Microstructure Evolution and Phase Transformation of Iron Produced from the Sustainable Carbothermic Reduction Process of High-Pressure Acid Leaching Residue.

This paper describes the microstructure evolution and phase transformation of residue from the lateritic nickel ore high-pressure acid leaching (HPAL) during carbothermic reduction using palm kernel shell (PKS) charcoal as a reductant. The study consisted of thermodynamic calculations combined with analysis of reduction experiments. The thermodynamic assessment predicted that the main phases formed during the reduction process were γ-Fe metal, liquid metal, slag, and spinel, with abundance of reducing gas (CO and H) at the temperature range of 750-1500 °C.

Thermodynamic analysis of caustic-roasting of electric arc furnace dust.

Electric Arc Furnace Dust (EAFD) is a byproduct of the steelmaking industry, which is one of the most significant and rapidly generated hazardous waste. This material includes recyclable elements such as zinc (Zn) and iron (Fe), exclusively in the form of zinc-ferrite (ZnFeO), zincite (ZnO), magnetite (FeO) with some other minor compounds of Si, Mn, Mg, and Pb. A combination of pyro and hydrometallurgical route, also known as hybrid process, has acquired considerable attention to extract Fe and Zn from electric arc furnace dust (EAFD).