Abstract: The invention relates to a fire resistant ceramic part which can be embodied in the form of an impact pot or a casting gutter and has the following characteristics:—a base (10);—at least two walls (12, 14) which extend from opposite sections (10l, 10r) of the base (10) such that at least some sectors (12.1, 12.3, 12.4) of the inner surfaces thereof run at an angle >0 and <90 degrees from a plane E—E, perpendicular to the base (10), and at opposite inclinations;—an opening (O) is configured between free ends (12r, 14r) of the walls (12, 14);—the distance (dmin, qmin) between the walls (12, 14) is smaller in at least one sector (11) between the base (10) and the opening (O) than it is in the areas (12u, 14u; 12o, 14o) located adjacent the opening (O) and the base (10).

Abstract: The present invention pertains to a device for preparing and feeding a monolithic ceramic mass into a metallurgical melting vessel, including a mixer 30 and a feeding device 32, characterized in that the mixer 30 and the feeding device 32 are designed as a compact unit 28 for arrangement above the metallurgical vessel, wherein the mixer 30 and/or the feeding device 32 are arranged relative to one another and movably such that the mass prepared in the mixer 30 can be directly introduced at any desired point of the metallurgical vessel via the feeding device 32.

Abstract: A magnesium oxide in fine powder form, which can be used to manufacture high-density ceramics, has an MgO content greater than 95 wt. %, preferably greater than 98 wt. %, a particle size less than 15 .mu.m, and a BET specific surface area less than 20 m.sup.2 /g. The statistical mean of the particle shape factor of the primary particles lies between 1 and 1.5. The particles are coated with a hydrophobic, surface-active substance.