Porosity dependence on thermal diffusivity and thermal conductivity of lithium oxide Li2O from 200 to 900°C

Abstract The porosity dependence on thermal diffusivity and thermal conductivity of Li 2 O was studied in the temperature range of 200 to 900°C. The relationship between thermal diffusivity α M and porosity P was expressed as α M = α T (1− ζP ), \ gz being 0.93, and also as α M = α T (1 + ηP) , η being 1.74 (200°C) ~ 1.11 (900°C). The relationship between thermal conductivity k M and porosity obeyed the generalized Loeb equation k M = k T (1− γP ), \ gg being 1.70, and obeyed the modified Maxwell-Eucken equation k M = k T (1−P) (1 + βP) , β being 1.81 (200°C) ~ 1.32 (900°C). Alternative empirical equations were also attempted as α M = α T (1− P ) m and k M = k T (1− P ) n , m being 0.91 and n = 1.06 . The temperature dependence on thermal diffusivity and thermal conductivity was found to be expressed as α = ( A ' + B ' T ) −1 and k = ( A + BT ) −1 . The pore correction factors are discussed in terms of porosity and temperature compared to published results.