Periclase-chromite refractories for steel-teeming ladles with ladle treatment of the steel

Abstract

Highly effective desulfurization of steel is obtained in ladles with linings of lime-Periclase and periclase-lime heat treated parts with a pitch or tar binder and the ladle life reaches 30-60 heats.At present measures are being taken for organization of the production of such refractories in shops for the production of converter parts for steel plants.In accordance with the general plan of development of the iron and steel industry a significant increase in ladle treatment of steel is planned. In connection with this the structure of production of ladle refractories must be sharply changed. A gradual reduction in the production of silica and chamotte refractories and an increase in the production of mullite, mullite-corundum, periclase, periclase-chromite, periclase-carbon, lime-periclase, and periclase-lime ladle refractories is planned (Fig. 2b). Nevertheless production of chamotte and silica refractories is also planned. The use is economically justified under conditions of treatment of steel with inert gases. The main share in the volume of production of ladle refractories is of basic and high-alumina refractories (more than 65%).The change in structure of the use of ladle refractories places before the refractory industry the task of the introduction and broadening the use of new forms of parts and compounds. The introduction of new forms of ladle refractories makes it possible to not only solve the problem of production of high-quality types of steel but also to sharply increase steel teeming ladle lining life to a level of not less than 30-50 heats of unformed refrac. tories and not less than 50-70 heats of ladle parts. In recent years in connection with introduction of the process of outside-the-furnace treatment of steel, including in the ladle, the question has arisen of use of refractories more resistant to metal and slag at high temperatures than aluminosilicate ones, the traditional ones for ladle linings. Such refractories may include basic refractories. Their use imposes special requirements on the service of ladles, particularly providing thermal conditions which would eliminate a reduction in lining temperature between heats. PERICLASE-CHROMITE REFRACTORIES FOR STEEL-TEEMING LADLES WITH LADLE TREATMENTThe method of preparing the lining (individual parts, poured, rammed, combined) and the material (basic, aluminosilicate, including high-alumina, etc.) depend in each specific case upon the service conditions, including the type and temperature of the metal teemed, the aggressiveness of the slag, and the capacity of the ladles.According to foreign data the preparation of a ladle lining completely with refractory parts with organic binders is promising. However, in our opinion under existing conditions at the present time the development of a pure method oftheir production and useis impossible. Grain-size distribution,

Results of the discussion

“…In view of the fact that effective works [i0, ii] on use of heat treated periclase-lime parts with resin and pitch binders have not yet been completed as the result of unsolved production and organizational questions, periclase-chromite refractories are used for the lining of ladles with ladle treatment. The authors of [12] showed that their life in the slag belt and bottom is twice the life of high-alumina parts.…”

Guniting of the nozzles of a circulation vacuum degasser

“…Such conditions of treatment of the steel are very unfavorable for service of refractories in vacuum degasser legs [1][2][3][4][5]. Such conditions of treatment of the steel are very unfavorable for service of refractories in vacuum degasser legs [1][2][3][4][5].…”