METHOD FOR PRODUCING HOMOGENEOUS FOAMED GLASS GRANULES

• Main Authors: FENTEN, NORBERT, KELLERMANN, MAX, SCHOTT, PETRA
• Format: Patent
• Language: English; French; German
• Published: 19.11.2003
• Edition: 7
• Subjects: CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; GLASS; JOINING GLASS TO GLASS OR OTHER MATERIALS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

The invention relates to a method for producing homogeneous foamed products. Glasses selected from the group of recycling glasses, synthetic glass, natural glass or mixtures thereof react with an aqueous alkali metal hydroxide solution and/or an alkali metal silicate solution as aqueous suspension at temperatures of 60 to 120 DEG C at normal pressure or in an autoclave. The reaction product obtained is removed as viscous mass, granulated and cooled until solid granules are obtained. The granules are expanded by heating which can be carried out in one or two steps. One-step heating is carried out at temperatures of 200 to 300 DEG C for a period of between two milliseconds and 15 minutes or at temperatures of 400 to 800 DEG C for a period of between two milliseconds and 15 minutes. Two-step heating is carried out at temperatures of 200 to 300 DEG C for a period of between two milliseconds and 15 minutes in the first step and at temperatures of 400 to 800 DEG C for a period of between two milliseconds and 15 minutes in the second step. The invention also relates to a foamed product produced by the inventive method.