Crystallity hydrated sodium metasilicates

Regardless of the t)q)e of soluble metal silicates used, they are subject to the same molecular speciation in aqueous solution resulting in a mixture of monomeric tetrahedral ions, oligomeric linear or cyclic silicate ions, and polysilicate ions. Sodium metasilicate, an example of a soluble metal silicate, can be prepared in anhydrous form or in the presence of water of crystallization as the penta- or nona-hydrate. It is readily soluble in water [8]. 

The sodium silicates are differentiated first of all by their molar ratio (or Rm), which traditionally is written Si02/Na20. The sodium metasilicates with Rm = 1 are often crystallized products, certain of which are used in dishwasher detergents. These crystallized products may be anhydrous, found as white powders of variable particle size, or they may be hydrated one of the most commonly used hydrates is the pentahydrated form, containing five molecules of water per silicon atom. 

Chester L. Baker, after an early indoctrination in the crystallization of commercial borax and other salts of Searles Lake, CA, in 1927, became Chief Chemist of the Philadelphia Quartz Co. of California, an affiliate formed in 1917 and owned 50% by the Stauffers. Baker arid later his assistant, Ralph Jue, worked long hours developing the phase relationships for the crystallization of hydrated metasilicates of sodium over... 

---