Refractories: Something Old and Something New

Extract

The earliest refractories for containing melts were quarried from natural deposits of limestone and dolomite. Today these two carbonate rocks serve important roles in the production of metal contact refractories. Early refractories for glass melting on the other hand were manufactured from clays and claystones. These materials are also still used extensively for the batch melting of glasses that are hand formed or blown into art and tableware. Glass contact refractories for the continuous (tank) melting of glass are often fired, cast into large shapes, and arranged in a soldier course which constitutes the sidewalls of the glass tank.

In this brief exposition of refractories technology and allied research, the articles by B. Brezny, T.F. Vazza and T.A. Leitzel, and by T.S. Busby cover materials development, selection, and properties of the systems which have evolved for the efficient melting of steels and glasses. As such they relate to extremes of technological flux in the processes for the manufacture of steel and glass, respectively.

The continuous melting of large volumes of commercial glasses has been carried out in tanks equipped with reverberators for at least 70 years. The basic design of the overall system and of many of the glass fabrication machines for pressing, rolling, and blowing the glass has been constant since World War I. Only the introduction of the float glass method, the famous Pilkington process, for the production of flat glass, has interrupted the slow quiet progress in the technology of continuous glass making.