CONSTITUTION AND THERMAL EXPANSION OF SILICA COKEOVEN BRICK AFTER SERVICE*

Abstract

Two silica brick which were in service in a coke oven for over ten years have been examined under the petrographic microscope. At the flue side the brick were almost completely converted to cristobalite, next comes a relatively thick layer which is mainly tridyinite, and finally mar the coke side quartz is found in addition. Measurements on small specimens taken from one of the brick show that the several layers have very different expanions. I t is concluded that in cooling a battery of ovens great care should be taken to cool slowly through the temperature range 200 to 300deg;C.