FORMATION OF COPPER-CHROMIUM SULFIDE SPINEL AND THERMAL-DECOMPOSITIONREACTIONS IN CUS-CR2S3 CRYSTALLINE MIXTURES

Differential thermal analysis-thermogravimetry (DTA-TG), X ray diffrac tion (XRD), and scanning electron microscopy (SEM) techniques were use d to study the formation of CuCr2S4 spinel and the thermal decompositi on reactions in crystalline mixtures of copper and chromium sulfides. The copper-chromium sulfide spinel was characterized by XRD and SEM an d the kinetics of formation was followed in the temperature range 200- 300 degrees C by a titrimetric method. Kinetic analysis in view of var ious solid-state reaction models showed that the reaction is best desc ribed by the diffusion models with an average activation energy 24.6 /- 1.6 kJ/mol. (C) 1995 Academic Press, Inc.