Abstract: A formulation usable to produce plates and shaped bodies has a base slip, quartz glass particles and multicomponent glass particles that are crystallizable or at least partly crystallized. The base slip contains water as dispersion medium with a content between 30% and 50% by weight and ultrafine SiO2 particles distributed, preferably colloidally therein, with a proportion between 50% and 70% by weight. The proportion of quartz glass particles in the formulation is in the range from 40% to 70% by weight and the proportion the multicomponent glass particles in the formulation is in the range from 5% to 37% by weight. The formulation can be used in a composite material. Firing aids can be made from the composite material.

Abstract: A process is disclosed for simple and rapid production of a shaped body comprising fused silica and a shaped body which leads to virtually no contamination of a melt in contact with the shaped body even at high temperatures. The disclosed process comprises the steps of: a) provision of fused silica in the form of essentially amorphous SiO2 grains of which not more than 5% have a diameter greater than 15 mm, b) addition of water to the fused silica grains to produce a slip, c) casting of the slip into a mold which comprises a hollow body having the inverse shape of the shaped body to be produced, and d) drying of the slip to give an intermediate body, which is then sintered and cooled. A shaped body producible in accordance with the aforementioned process is also disclosed, which comprises at least 99.0 mol % of SiO2.

Abstract: For simple and rapid production of a shaped body comprising fused silica and a shaped body which leads to virtually no contamination of a melt in contact with the shaped body even at high temperatures, the invention provides a process comprising the steps: a) provision of fused silica in the form of essentially amorphous SiO2 grains of which not more than 5% have a diameter greater than 15 mm, b) addition of water to the fused silica grains to produce a slip, c) casting of the slip into a mould which comprises a hollow body having the inverse shape of the shaped body to be produced, d) drying of the slip to give an intermediate body, e) sintering of the intermediate body at a sintering temperature at which at least part of the fused silica is transformed from the amorphous modification into a crystalline modification, f) cooling of the sintered shaped body to a temperature below 300° C., so that a microstructure containing crystalline SiO2 is formed, and also a shaped body which comprises at least 99.