New Method of Preparation of Rare Earth Metals Carbothermal Reduction of Their Oxides

摘要

The study of the reduction of lanthanum sesquioxide (cerium group) and erbium sesquioxide (yttrium group) has been made versus the pressure of carbon monoxide. It has shown the existence of two equilibrium reactions in the case of lanthanum, and of only one reaction for erbium. The relationship of equilibrium pressures to the temperature permitted the calculation of thermodynamic values of resulting carbides and oxicarbides. The lanthanum, neodymium, gadolinium, dysprosium, erbium and yttrium dicarbides were prepared by carbothermic reduction of the sesquioxides in solid state. Conditions for obtaining products containing very little oxygen were determined. The melting of these fritted carbides in the solar furnace decreases considerably both their amount of oxygen and their hydrolysability. This treatment improves also their homogeneity. (ERA citation 06:023926)