Abstract: The present invention resides essentially in that a proposed mixture comprises an aluminium powder, nitre and a silica-containing component, the mixture composition, according to the invention, incorporating, apart from said constituents, calcium oxide, expanded pearlite or fluorspar, and a silicon-containing component. The proposed mixture provides for the burning thereof with subsequent formation of molten slag therefrom adapted for refining steel in a ladle.

Abstract: A roof in which beams-headers rest on a roof ring and carry loop-shaped tubes suspended from and coupled with the said beams-headers which are running transversely to the framework tubes. Welded edgewisely to the top generatrices of the tubes are metal straps with bricks placed at least in one layer in rows therebetween. The brick end portions rest on the adjacent tubes, so that the brick in each row are disposed with a clearance sufficient to enable thermal expansion of the brick both vertically and horizontally when heated.