CaO-Al_2O_3 系溶融スラツグの電氣傳導度

概要

論文の詳細を見る
The authors have already made clear the structure of simple molten slags containing SiO_2 through the electrical conductivity of several RmOn-SiO_2 (RmOn : basic oxides) systems. Such investigations being extended in order to study the behaviours of Al_2O_3 in molten slags, the electrical conductivity of the system CaO-Al_2O_3 was measured over the temperature range 1, 600∿1, 400℃ and the composition range 41∿58 wt.% Al_2O_3. Samples were melted in a graphite crucible, a Tammann-furnace being used. Two graphite rods were used for the electrodes. The measurements were done making use of the conventional apparatus of bridge-method by alternating-current. The specific electrical conductivities (κ) increased with the rise of temperature (T : °K) and with the increase of CaO content. In the conductivity-temperature curves one anomalous point appeared. Generally at the higher CaO range this point corresponded to the temperature of solidifying, but at the lower CaO the rate of decrease of conductivity with temperature becomes smaller. The interpretation of the latter phenomenon was difficult. The relation between log κ and I/T obeyed to the formula of In κ=-Q/RT+B (Q ; Activation energy, R : gas constant and B : constant) in molten state. From the fact that the specific electrical conductivities are in the order of 0.1∿1 Ω^<-1>cm^<-1> and that the values of the energy of activation for ionic migration are 25∿47 Kcal/g-mol, it was concluded that the conductance was ionic. In the CaO-Al_2O_3 system CaO existed as Ca^<++> and Al_2O_3 as aluminate ion or Al^<+++>, and perhaps the mechanism of conductivity would be controlled mainly by Ca^<++>. In the conductivity-composition curve maximum value appeared at the composition 5CaO・3Al_2O_3. Both the energy of activation Q and the constant B were divided into two groups by he composition corresponding to 5CaO・3Al_2O_3. At the lower Al_2O_3 range they were small, and besides at the higher Al_2O_3 they were large. These facts indicated that the tendency of the formation of 5CaO・3Al_2O_3 remained even in molten state. The amphoteric behaviour of Al_2O_3 in molten slags was also discussed. Much to our regret the data were lacking in viscosity for the purpose of assuming the forms of aluminate ions in molten slags.
社団法人日本鉄鋼協会の論文
1952-08-25

CaO-Al_2O_3 系溶融スラツグの電氣傳導度

スポンサーリンク

概要

著者

関連論文

スポンサーリンク