A furnace may include a furnace muffle that can accommodate relatively larger workpieces than other furnaces. The furnace muffle may include a cover that includes one or more sets of plates. The plates may be configured to prevent sag during extended runtimes while still enabling the furnace to reach a temperature (e.g., a temperature between 1590° C. and 1650° C.) for sintering a workpiece. In some examples, the cover may include a first set of plates of a first material (e.g., a first alumina refractory material) and a second set of plates of a second material (e.g., a second alumina refractory material). The second material may have greater thermal conductivity than the first material. Accordingly, plates of the second set may be located in higher temperature zones of the furnace to enable efficient heat transfer from heater elements through the furnace muffle to a contact plate where a workpiece is heated.

A furnace may include a furnace muffle that can accommodate relatively larger workpieces than other furnaces. The furnace muffle may include a cover that includes one or more sets of plates. The plates may be configured to prevent sag during extended runtimes while still enabling the furnace to reach a temperature (e.g., a temperature between 1590° C. and 1650° C.) for sintering a workpiece. In some examples, the cover may include a first set of plates of a first material (e.g., a first alumina refractory material) and a second set of plates of a second material (e.g., a second alumina refractory material). The second material may have greater thermal conductivity than the first material. Accordingly, plates of the second set may be located in higher temperature zones of the furnace to enable efficient heat transfer from heater elements through the furnace muffle to a contact plate where a workpiece is heated.

Refractory anchoring devices include a main body and a mounting feature for mounting to a thermal vessel. The main body includes four anchor branch segments angled with respect to each other to form an X shape with four unenclosed cell openings, including two opposite triangular side openings and two opposite triangular end openings. In some embodiments, the main body further includes extension segments extending from and angled relative to respective branch segments to define two of the opposite openings as semi-hexagonal. Some embodiments include reinforcement segments extending from branch segments into openings, voids extending through branch segments, two anchor strips inter-engaged to form the four branch segments, and/or a single stud-welding stud for the mounting feature. Refractory anchoring systems and methods include an array of the refractory anchoring devices arranged and mounted so that the unenclosed openings of adjacent anchoring devices cooperatively form substantially hexagonal and rhombus shaped cells.

Refractory anchoring devices include a main body and a mounting feature for mounting to a thermal vessel. The main body includes four anchor branch segments angled with respect to each other to form an X shape with four unenclosed cell openings, including two opposite triangular side openings and two opposite triangular end openings. In some embodiments, the main body further includes extension segments extending from and angled relative to respective branch segments to define two of the opposite openings as semi-hexagonal. Some embodiments include reinforcement segments extending from branch segments into openings, voids extending through branch segments, two anchor strips inter-engaged to form the four branch segments, and/or a single stud-welding stud for the mounting feature. Refractory anchoring systems and methods include an array of the refractory anchoring devices arranged and mounted so that the unenclosed openings of adjacent anchoring devices cooperatively form substantially hexagonal and rhombus shaped cells.

Refractory anchoring devices include a main body and a mounting feature for mounting to a thermal vessel. The main body includes four anchor branch segments angled with respect to each other to form an X shape with four unenclosed cell openings, including two opposite triangular side openings and two opposite triangular end openings. In some embodiments, the main body further includes extension segments extending from and angled relative to respective branch segments to define two of the opposite openings as semi-hexagonal. Some embodiments include reinforcement segments extending from branch segments into openings, voids extending through branch segments, two anchor strips inter-engaged to form the four branch segments, and/or a single stud-welding stud for the mounting feature. Refractory anchoring systems and methods include an array of the refractory anchoring devices arranged and mounted so that the unenclosed openings of adjacent anchoring devices cooperatively form substantially hexagonal and rhombus shaped cells.

An unfired, refractory molded body (1), includes a binding agent matrix (2) containing at least one set, permanent binding material and aggregate grains (3) with and/or of biogenic silicic acid, preferably with and/or of rice husk ash, which grains are incorporated into the binding agent matrix (2), for thermal isolation of a molten metal, especially of molten steel, and/or of a metal ingot solidifying from the molten metal, and also the use of the molded body (1) for thermal isolation of a refractory lining, in particular in a multiple-layer brick wall or in a heat-treatment furnace, or as a corrosion barrier, e.g. against alkali attack, or as a fire protection lining or as filter material for hot gases.

An unfired, refractory molded body (1), includes a binding agent matrix (2) containing at least one set, permanent binding material and aggregate grains (3) with and/or of biogenic silicic acid, preferably with and/or of rice husk ash, which grains are incorporated into the binding agent matrix (2), for thermal isolation of a molten metal, especially of molten steel, and/or of a metal ingot solidifying from the molten metal, and also the use of the molded body (1) for thermal isolation of a refractory lining, in particular in a multiple-layer brick wall or in a heat-treatment furnace, or as a corrosion barrier, e.g. against alkali attack, or as a fire protection lining or as filter material for hot gases.

An unshaped product including, as weight percentages, A) particles (a) of at least one refractory material other than a glass and a glass-ceramic, and the main constituent(s) of which are alumina and/or zirconia and/or silica and/or chromium oxide: B) 2% to 15% of particles (b) of a hot binder chosen from glass-ceramic particles, particles made of a glass, and the mixtures of these particles, a glass being a noncrystalline material exhibiting a glass transition temperature of less than 1100° C., the hot binder not being in the solid state at 1500° C., C) less than 2% of particles (c) of hydraulic cement, D) less than 7% of other constituents, the particles (a) and (b) being distributed, as weight percentages in the following way: fraction<0.5 μm: ≥1%, fraction<2 μm: ≥4%, fraction<10 μm: ≥13%, fraction<40 μm: 25%-52%.

An unshaped product including, as weight percentages, A) particles (a) of at least one refractory material other than a glass and a glass-ceramic, and the main constituent(s) of which are alumina and/or zirconia and/or silica and/or chromium oxide: B) 2% to 15% of particles (b) of a hot binder chosen from glass-ceramic particles, particles made of a glass, and the mixtures of these particles, a glass being a noncrystalline material exhibiting a glass transition temperature of less than 1100° C., the hot binder not being in the solid state at 1500° C., C) less than 2% of particles (c) of hydraulic cement, D) less than 7% of other constituents, the particles (a) and (b) being distributed, as weight percentages in the following way: fraction<0.5 μm: ≥1%, fraction<2 μm: ≥4%, fraction<10 μm: ≥13%, fraction<40 μm: 25%-52%.

A method for reducing molten raw materials, includes placing the raw materials, in a solid or molten state, on an inductively heated bed with coke pieces. The reduced melt that runs off the coke bed is collected and the waste gases are discharged. A coke bed is inwardly limited by a tube-shaped element through which the reaction gases are drawn off via a plurality of draw-off openings in the tube-shaped element. The corresponding device has a reactor for a bed with coke pieces and an induction heater with at least one induction coil. The reactor has a loading opening and a discharge opening for the treated melt. The coke bed is ring-shaped around a tube-shaped element. The material of the tube-shaped element allows inductive coupling to the induction field of the induction coil and it has draw-off openings for drawing off reaction gases from the coke bed.