Silicothermic Reduction of Thanhhoa Dolomite: Thermodynamic and Experimental

Abstract

Thermodynamic and experimental studies was carried out on the process of Thanhhoa dolomite reduction to produce magnesium. Thermodynamically studied on the effect of pressure and temperature on reduction was carried out together with verification experiment. Results show that at appropriate temperature and vacuum pressure, Thanhhoa dolomite can be reduced using ferrosilicon as the reductant. The higher level of vacuum, the lower temperature required for reduction. Thermodynamic calculation pointed out that at a vacuum pressure of 600 Pa, the reduction temperature could be as low as 1140 °C. Experiment results indicated that at although reduction could be done at 1150 °C, the process efficiency was low, generally below 20%. Process efficiency enhanced as temperature increase and reaches the highest value of 85,8% at 1250 °C (25 wt.% ferrosilicon). The amount of ferrosilicon used also has influenced the process efficiency. After three hours of reduction, the obtained magnesium was very high in purity, 99.3%.

Thermodynamic Diagram Analysis and Smelting of Complex Fe-Cr-Mn-Si Ferroalloy

“…In metallurgy theory and practice, studying the state of materials involved in metallurgical conversion, depending on temperature and pressure, is significant. Conducting in-depth physicochemical research, which provides a theoretical foundation, is critically important for improving metal quality and implementing new promising technologies, based on which further smelting trials can be more easily controlled [10,11]. Yet, classical thermodynamic studies of processes in complex systems require complex mathematical calculations and the determination of thermodynamic parameters for many independent reactions [12][13][14].…”