A NEW PROCEDURE FOR MEASURING THE THERMAL-DIFFUSIVITY OF NONMETALLIC MELTS AT HIGH-TEMPERATURES

A new procedure for measuring the thermal diffusivity of non-metallic melts at high temperatures has been developed, and a measuring set up based on thermography and the use of a CO2 laser has been constructed. The working efficiency of the measuring procedure, together with the accuracy and reproducibility of the measured values have been checked by measurements on synthetic slags. The thermal diffusivities of synth etic slag (38% CaO-38% SiO2 . 19% Al2O3-5% Fe2O3) at temperatures from 1648 to 1740 K lie between 2.6x10(-7) and 3.0x10(-7) m(2)s(-1). The m ean deviation of measured values is about +/-6%. The advantages of thi s new procedure are compared with usual laser flash methods and possib le error sources are discussed.