SMS are a powder form of anhydrous sodium metasilicate. SMS are normally dry blended and used as an extender in oilwell cements. Light weight slurries can be formulated by blending SMS with the lime present in cement or by the addition of calcium chloride to produce a calcium silicate gel. This gel structure creates enough viscosity to allow for additional mix water without the problem of excess free water separation.
SMS may accelerate the set time of some cement blends. SMS are normally added in a concentration of 0.1% to 3% by weight of cement. Resulting slurry densities range from 1350-1750 kg/m³.