Quantiative Study Of Reaction Products From Absorption Of Alumina From Crucibles Into A Barium Aluminosilicate Melt

Recrystallised alumina crucibles are often used for melts which would damage platinum or gold crucibles. The take-up of alumina from the crucibles into the melt is a well know problem. An attack line can often be seen at the mensicus as well as thinning of the walls of the crucible below the mensicus after the glass has been poured. However, no quantitative analysis seems to have been reported for melts in alumina crucibles. This paper presents results for glasses in the system BaO-Al203-Si02 melted in alumina crucibles and show that approximately 20 mol% Al203 is absorbed into the melt and a concentration gradient penetrates about 1.5mm into the melt from the crucible.