THERMODYNAMIC CONSIDERATION OF THERMAL PLASMA PROCESS FOR ZIRCONIUM CARBIDE PRODUCTION FROM ZIRCON CONCENTRATES

Improved zirconium ceramics and composites have been invented in an effort to obtain better resistance to ablation at high temperature. These ceramics are suitable for use as thermal protection materials on the exterior surfaces of spacecraft, and in laboratory and industrial environments that include flows of hot oxidizing gases.
Results of thermodynamic consideration of the process for zirconium carbide ultrafine powder production from ZrSiO₄ in argon thermal plasma and methane or propane-butane gas as reactive quenching reagents are presented in the paper. Equilibrium composition and total enthalpy values (including heat of formation of species and latent heat of phase transformation) of the Zr_Si_O_C_H_Ar system in temperature interval 1000 K to 6000 K at pressure of 1 bar, enable optimal plasma process routes consideration, and determination of temperature, mass and energy parameters of the process.