TEMPERATURE CONTROL AND CALIBRATION IN QUENCH FURNACES AND SOME NEW TEMPERATURE MEASUREMENTS IN SYSTEM CAO-MGO-AL2O3-SIO2

Techniques associated with temperature control and measurement in quench furnaces are described and a study made of calibration problems. Systematic temperature errors as great as 30 C in published results from separate laboratories are explicable. A comprehensive redetermination of temperatures of invariant equilibria in systems containing CaO, MgO, Al//2O//3, SiO//2, Na//2O, Fe- O//2, has been initiated and the results to date are presented, including approximate determinations of three invariant equilibria in the system CaO- MgO- Al//2O//3- SiO//2 involving liquid, monticellite, spinel, and two of merwinite, periclase, and forsterite.