Polysilicates, hydrous sodium powders

Hydrous sodium polysilicate powder Sodium silicate solutions... 

Hydrous sodium polysilicate powders are manufactured by removing a part of the water content of the corresponding silicate solutions through drum or spray drying (see Table 22.1) [1,7,8,17-19,21,49]. 

FIGURE 22.5 Spray drying process for the production of hydrous sodium polysilicate powders. 

Hydrous sodium polysilicates are available as powders with bulk densities from 80 to 650 g/L and compacted granules with bulk densities in the range 750-950 g/L. Particle sizes are between 80 and 700 pm [2,11,65]. Made from sodium silicate solutions, they may contain 16-22 wt% moisture [1,5,7,11]. Water uptake is generally limited by their tendency toward caking at higher moisture levels. They are x-ray amorphous and have no defined stoichiometry [19,65]. The composition is... 

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