X-ray Studies on the Chrome-Magnesia Bricks used in an Open-Hearth Furnace

Studies on the Refractories used in an Open-Hearth Furnace (VIII)

Abstract

Microscopical and chemical studies on the mechanism of corrosion of chrome-magnesia refractories used in an open-hearth furnace were reported in previous papers, and the present one contains the results of X-ray studies on the constitutional minerals (spinel periclase and matrix minerals) in every zones of the burned chrome-magnesia brick from the front wall and the unburned brick from the zebra roof of basic open-hearth furnace.
The lattice constants of original chromite spinel separated from the lowest temperature (unaltered) zone, magnetite spinel in the working face of the burned brick and that embeded in a silicious glass matrix in the unburned brick from zebra roof were 8.21, 8.35 and 8.40 Å respectively. This expansion of the spinel due to the variation of its chemical composition is connected with the bursting phenomenon of the brick.
Augite is a predominant constitutional mineral of matrix in the hottest face, and forsterite and monticellite are principal matrix minerals in the middle zone of the brick.