Optimal thermal plasma processes for zirconium carbide powder production from zircon concentrates

Abstract

Available results of equilibrium composition and total enthalpy computation for the systems: Zr-Si-O-Ar and Zr-Si-O-C-H-Ar? presented in the paper, enables thermodynamic optimization of the plasma process for zirconium carbide production from zircon. In the first step of the considered process, zircon decomposition to zirconia and silica is followed by their evaporation in argon thermal plasma. In the second step by introduction of methane or propane-butane gas in the Zr-Si-O-Ar system and reactive quenching, the temperature of such obtained Zr-Si-O-C-H-Ar is lowered to a range in which it is possible to deposit zirconium carbide powder. On presented examples the procedure of determination of optimal mass, energy and temperature process parameters is demonstrated. From presented data, it is possible to calculate and optimize process parameters for any other thermodynamic conditions. (C) 2001 Elsevier Science Ltd and Techna S.r.l. All rights reserved.