METHOD FOR PRODUCING HIGH-PURITY POWDERED CRISTOBALITE FROM SILICON DIOXIDE Russian patent published in 2021 - IPC C01B33/12 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing cristobalite. A method for producing high-purity powdered cristobalite is described, consisting in the fact that powdered amorphous silicon dioxide is poured into a quartz glass furnace and subjected to two-stage thermal processing, wherein the powdered amorphous silicon dioxide after being poured into the furnace is diluted with a 0.5÷5% aqueous solution of nitric acid, wherein the resulting mixture is sustained while stirring and heating to 90÷95°C for 40 minutes, followed by settling, decanting and washing twice with deionised high-purity water followed by drying at a temperature of 150±1°C for 90 minutes, two-stage thermal processing of the powdered dried product is then conducted first at a temperature of 1000±5°C for 60 to 90 minutes in a high-purity air stream and then at a temperature of 1250 to 1300°C±5°C for 2 to 4 hours, thereby forming high-purity powdered cristobalite in the furnace.

EFFECT: production of high-purity powdered cristobalite.

3 cl, 2 ex