Sodium pyrosilicate → Sodium orthosilicate

Participants

Reaction Steps

EP-A-0 444 415 proposes detergents containing 5 to 50% by weight of at least one surfactant, 0.5 to 60% by weight of a builder and typical detergent ingredients, characterized in that an amorphous low-water sodium disodium disilicate with a water content of 0.3 to 6% by weight is used as the builder. In a preferred embodiment, the amorphous sodium disilicate is said to contain 0.5 to 2% by weight of water. These substantially water-free amorphous disilicates are produced by a multistage process which initially comprises producing a powder-form amorphous sodium silicate with a water content of 15 to 23% by weight. This material is treated with waste gas in countercurrent in a rotary kiln at temperatures of 250° to 500° C. The amorphous sodium disilicate issuing from the rotary kiln is size-reduced by a mechanical crusher to particle sizes of 0.1 to 12 mm and subsequently ground in a mill to particle sizes of 2 to 400 μm.

Provenance & Evidence