Chlorination of RuO2 with gaseous Cl2 between 998 and 1123 K

C.GUIBALDO; G. DE MICCO; A. E. BOHÉ

Procedia Materials Science

Elsevier

Año: 2015 vol. Ruth p. 841 - 850

2211-8128

Employing methods of separation based on selective chlorination it is possible to separate valuable components, such as metals andrare earths, from ores and / or solid wastes. In this paper we study the chlorination reaction of ruthenium oxide. This element isamong nuclear fission products, also part of many electronic wastes and numerous catalysts in the chemical industry. The study ofthe chlorination reaction of ruthenium oxide will allow to analyze in which conditions it is possible to apply gaseous chlorination forruthenium recovery. No systematic studies on the kinetics and chemical mechanism of ruthenium oxide chlorination are availablein the literature. In the present study, we performed a thermodynamic analysis of possible reaction pathways. The reaction productswere identified by scanning electron microscopy (SEM) and x-ray Diraction (XRD), and the experimental conditions for obtainingstable -RuCl3 by RuO2 chlorination and subsequent heating in Cl2 were established. The starting temperature for the chlorinationwas determined at 983 K. The observed mass loss is due to formation of volatile products. We analyzed the eects of gas flow rate,crucible geometry, and sample mass on the kinetics of the reaction, in order to establish the corresponding experimental reactionconditions for chemical kinetic control. The eect of temperature was analyzed and an apparent activation energy of 173 8kJ.mol􀀀1 was obtained for the chlorination reaction.