Abstract: The light guide and the method of measuring temperature with the aid of said light guide relate to optical pyrometry of melts.A light guide 1 is made from a light-permeable refractory corrosion-resistant material such as leucosapphire, for example, and according to the invention comprises 2 portions: a narrow portion 2 in the form of a rod, and a large portion 3 with a flat end 3a being an operating end of the light guide 1. The large portion 3 of the light guide 1 represents with respect to the narrow portion 2 an optical cavity producing radiation of the operating end 3a substantially in the form of a radiation of an absolutely black body. The ratio of the cross-section area of the narrow portion 2 at the place where it adjoins the large portion 3 does not exceed 0.5.

Abstract: The proposed method relates to metallurgy and foundry engineering.The process of lining a metallurgical assembly, in particular an induction furnace (1) is carried out in the following sequence. First, a bottom (2) is lined using a conventional method, following which a gauge (3) for forming an inner wall of the furnace lining is mounted thereon, and a space (5) provided within the gauge (3) and an induction heater (4) of the furnace (1) is filled with a lining mass (6). The lining mass is filled in layers each having a thickness of 4 to 10 values of said space (5). The layers are compacted by applying periodically repeated blows against the inner surface of the gauge (3). These blows are applied in the direction perpendicular to a plane tangential to said surface of the gauge (3), the interval between the blows being not less than the damping time of free oscillations of the furnace.The above described method may be used when carrying out rammed lining within coreless induction furnaces.

Abstract: A light-guide unit comprises a light-forming rod and a light-transmitting rod, both rods being made from a light-permeable corrosion-resistant refractory material, for instance synthetic corundum, and coaxially arranged relative each other. According to the invention the length of the light-forming rod is equal to the thickness of the metallized layer of a lining, and the length of the light-transmitting rod is not less than the thickness of the remaining portion of the lining. The rods are connected by a protection sleeve made from a material featuring plasticity at the operating temperature of the lining, and disposed in the tube. The tube at the portion wherein the light-forming rod is disposed is filled with a first refractory material having a sintering temperature not higher than the sintering temperature of the lining, and whose resistance to the action of the products of melting is similar to that of the lining.

Abstract: A refractory powder for use in a light guide assembly for transmitting a thermal radiation from a melt to a pyrometer through the lining of a metallurgical vessel.The proposed powder has the following composition (by wt. %); aluminum oxide from 40 to 70, silicon dioxide from 29 to 59, and a sintering agent from 0.3 to 2.0. As the sintering agent use is made, in particular, of a boric acid.According to the proposed method the aluminum oxide powder and the silicon dioxide powder are heated to a temperature of from 1200.degree. to 1400.degree. C. and from 900.degree. to 1200.degree. C. respectively, then cooled to a room temperature and mixed with simultaneously adding thereto a sintering agent until a uniform mixture is produced.