Metasilicate granulated

Later he brought out the sesquisilicate and later still worked out the process for a granulated sodium metasilicate. 

Drying a solution of metasilicate in a special drum granulator drier is commonly used in industry (see Table 22.1) [15,79,80]. The aqueous sodium silicate solution is prepared from alkaline sodium silicate liquor and caustic soda (see Figure 22.9). 

FIGURE 22.9 Granulation process for the production of anhydrous sodium metasilicate. 

In the drum granulation process, a plurality of small solid particles of anhydrous metasilicate are fed into the end of a revolving drum, thus forming a moving bed. 

Vrisakis, G., Chastel, J. 1981. Granulation of sodium metasilicate. US4253849. Rhone-Poulenc Industries. 

Joubert, D., Parker, P. 1989. Use of metasilicate/silica combination granulate in detergent compositions for washing machines. US4844831. Rhone Poulenc Chimie. 

The most commonly used silicates in detergency are the sodium silicates. The sodium silicates used as builders are in the form of powders or solid granules, which may be crystalline or amorphous, hydrated or anhydrous. Among these solid forms are found metasilicates with Rm = 1, and also some of higher ratio, where Rm = 2 to 3.5. These higher-ratio silicates are commercially available as concentrated aqueous solutions as well. 

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