Sodium pyrosilicate → Sodium orthosilicate

Participants

Reaction Steps

Amorphous sodium disilicates with a low water content of 0.3 to 6% by weight are known from European patent application EP-A-0 444 415. The amorphous sodium disilicate is said preferably to contain 0.5 to 2% by weight of water. These amorphous disilicates with their very low water contents are produced by a multistage process in which a powder-form amorphous sodium silicate with a water content of 15 to 23% by weight is initially prepared. This material is treated in countercurrent with waste gas at temperatures of 250° to 500° C. in a revolving tube furnace. The amorphous sodium silicate leaving the revolving tube furnace is size-reduced to particle sizes of 0.1 to 12 mm by means of a mechanical crusher and is then ground in a mill to particle sizes of 2 to 400 pm.

Provenance & Evidence