Abstract: A method for measuring the thickness of a refractory laid-up against the interior surface of the steel shell of a metallurgical apparatus includes placing at least one monitoring device in a critical wear area of the apparatus in a manner such that the free end of the device is at a known distance from the hot face of the refractory and the confined end extends beyond the outer surface of the steel shell. The device is connected to an electronic time-domain reflectometer by electrical connecting means. Timed pulses are generated and impressed in the device by the instrument and reflections of the pulses are received by and are visually displayed on the reflectometer. The length of the device appears on the display as a straight line bounded by two inflections. The straight line is indicative of the thickness of the refractory.The device includes a metallic conductor coaxial with an outer metallic sheath and separated therefrom by a refractory having a desired dielectric constant.

Abstract: Basic refractory shapes in selected critical wear areas of a working lining in a basic oxygen furnace are protected from spalling due to thermal shock during "burn-in" and initial operation of the working lining and during the early part of a furnace campaign. A plurality of securing means comprising relatively thin, elongated, flat, generally rectangular anchors are positioned in selected joints in the working lining during installation. The anchors extend a distance beyond the hot faces of the working lining. A reticulated reinforcing means comprising a metallic grid is fastened to the anchors in spaced relationship to the hot faces. A layer of a pulverulent basic refractory material having a thickness sufficient to cover the anchors and metallic grid is sprayed over the working lining in the critical wear areas. The layer of sprayed material provides an effective insulation over the basic refractory shapes in the critical wear areas during "burn-in" of the working lining in the furnace.