金属ヒ化物およびアンチモン化物（ＭｘＡｓｙ， ＭｘＳｂｙ（Ｍ＝Ｃｕ， Ｆｅ， Ｃｏ， Ｎｉ））の熱測定

Abstract

Calorimetric investigations were conducted for some arsenides and antimonides as a fundamental study of the speiss phase in nonferrous pyrometallurgical processes.Heat contents of four arsenides (Fe2As, Co5As2, Ni5As2 and Cu3As) and four antimonides (Fe3Sb2, CoSb2, Ni5Sb2 and Cu2Sb) were determined over a temperature range of 800 to 1, 500K using a drop calorimeter. Temperature coefficients of the heat content were determined by a regression analysis method using the Shomate function. Heat capacities of these compounds at high temperatures were also derived from the heat content temperature coefficients.Heats of formation of four arsenides (Fe2As, Co5As2, Ni5As2 and Cu3As) were determined at 298K using a Tian-Calvet type solution calorimeter. By combining the heats of formation and heat capacities obtained in this study with literature values of standard entropy, the standard Gibbs free energy changes of formation of these arsenides were determined as a function of temperature.Distributions of copper, iron, cobalt and nickel between speiss and metal, matte or slag phases were thermodynamically discussed based on the free energy data for the arsenides.