Method for producing a composite body of a material with a high silicic acid content

A method for producing a composite body comprising a first layer of a material having a high silicic acid content and a first additional component in a first concentration connected to a second layer of a material having a high silicic acid content and a second additional component in a second concentration that differs from the first concentration, wherein the first and the second concentrations are greater than or equal to zero, the method comprising the following steps:

• (a) preparing a first slurry layer having a free surface from a first slurry mass containing first SiO2 particles and the first additional component in the first concentration dispersed in a first dispersing agent,
• (b) providing a second slurry mass containing second SiO2 particles and the second additional component in a second concentration that differs from the first concentration dispersed in a second dispersing agent,
• (c) forming a composite-body intermediate product by applying the second slurry mass to the free surface of the first slurry layer, and
• (d) heating the composite-body intermediate product while forming the composite body.