Thermodynamic modeling reduction of metals by hydrogen from ilmeniite concentrate and experimental verification the results.

Abstract

It is shown that existing methods of hydrometallurgical and pyrometallurgical processing of ilmenite concentrates do not meet the requirements of rational environmental management. Pyrometallurgical methods for processing ilmenite concentrates involve the use of carbon as a reducing agent, which complicates the process of their processing due to the possibility of the formation of titanium carbides. As an alternative to carbon as a metal reducing agent, the work proposes the use of hydrogen gas. The results of thermodynamic calculations and experimental studies and their comparison in the reduction of metals by hydrogen from ilmenite concentrate are presented. The results have discrepancies associated with the kinetics of the processes that are not taken into account in the thermodynamic calculation. According to the results of thermodynamic calculations, part of the iron is bound in complex oxides CaFeSiO4 and FeAl2O4, the formation of which prevents the complete reduction of iron, however, in the experiment it is possible to obtain a higher degree of iron metallization compared to the calculated one. The impossibility of the formation of complex oxides CaFeSiO4 and FeAl2O4 in the experiment can be explained by the location of Ca, Si and Al, which are contained in the concentrate in the form of individual impurity particles of waste rock. Reduction of titanium to metal is impossible according to the results of thermodynamic calculation, but its partial reduction with the formation of oxide to TiO is possible. According to the experimental results, partial reduction of titanium leads to the formation of a new anosovite phase (Ti3O5). Impurity Si and Mn that are found in waste rock particles are not reduced, because their reduction requires the presence of iron-based solution according to the results of thermodynamic calculation