1992 Fiscal Year Final Research Report Summary

Trial Manufacture of Basicity Sensor for Molten Slag

Research Project

Project/Area Number	03555143
Research Category	Grant-in-Aid for Developmental Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	金属精錬・金属化学
Research Institution	Tokyo Institute of Technology
Principal Investigator	NAGATA Kzuhiro Tokyo Institute of Technology, Department of Metallurgical Engineering, Professor, 工学部, 教授 (70114882)
Co-Investigator(Kenkyū-buntansha)	MATSUOKA Masao Yamari-Electronite Co., Managing Director, 専務取締役研究所長 MARUYAMA Toshio Tokyo Institute of Technology, Department of Metallurgical Engineering, Associat, 工学部, 助教授 (20114895)
Project Period (FY)	1991 – 1992
Keywords	Calcium Phosphate / Solid Electrolyte / Calcium Sensor / Molten Slag / Activity / Basicity Sensor / Calcium Oxide / Alminium Oxide
Research Abstract	The activity of calcium oxide in molten CaO-Al_2O_3 with 0.55 to 0.73 mo1%CaO was measured during 1573 and 1873K in air by means of the Galvanic cells using 4CaO.P_2O_5 compound as a solid electrolyte. The solid electrolyte is tablet with about 10 mm in diameter and 3 mm in thickness. The electromotive forces of the cells have good reproducibility and the temperature at which the slope of electromotive force charges excellently coincides with the transformation temperature written in the phase diagram of CaO-Al_2O_3 system. The activity of CaO deviates from the Raoulian atandard and that of Al_2O_3 calculated by the Gibbs-Duhem equation also deviates from the Raoulian atandard. The stable electromotive force of the Galvanic cell using a 4CaO. P_<>O_5 solid electrolyte gave the activity of Ca in molten Ca-Ag. The activity of CaO in molten CaO-Al_2O_3 slag equilibrated with molten steel can be thermodynamically determined from two of the activities of Ca, Al, O in the molten steel. The activities of O and Al in molten steel were measured in a steelmaking industry using oxygen and aluminium sensors. In order to examine the equilibrium relation between CaO, Al_2O_3 and ZrO_2, the phase diagram of their elements was experimentally drawn.