Patent ID: 8609019

Claim:
A method for producing a refractory molded body using a material composition having a fine-grained fraction with grain sizes below 100 μm and a coarse-grained fraction with grain sizes above 100 μm, the method comprising: adding a dispersing agent and/or a liquefier to the material composition unless the material composition already comprises the dispersing agent and/or liquefier; forming the material composition into a molded body; and sintering the molded body at a temperature above 1300 degrees Celsius, wherein the fine-grained fraction comprises: aluminum oxide in a percentage by weight of at least 90% of a total weight of the fine-grained fraction and including a grain size of 50 nm to 100 μm, zirconium oxide in a percentage by weight of greater than 0% and up to 5% of the total weight of the fine-grained fraction and with the grain size of between 50 nm and 20 μm, a stabilizer for the zirconium oxide, and titanium oxide powder in a percentage by weight of greater than 0% and up to 5% of the total weight of the fine-grained fraction and with the grain size of between 50 nm and 20 μm, wherein the coarse-grained fraction constitutes a percentage by weight of more than 30% of the material composition and comprises aluminum oxide based crushed granulate and/or aluminum oxide based hollow-sphere structures, and wherein at least part of the coarse-grained fraction has previously been prepared from the fine-grained fraction by sintering the fine-grained fraction or allowing the fine-grained fraction to solidify from a melt and then breaking the solidified fine-grained fraction down.