ABSTRACT
Sodium silicate is not a compound in the normal sense of the word, but is a mixture of sodium oxide (Na2O), silica (SiO2) and water; solutions with weight ratios of SiO2 to Na2O between 1.6 and 4 or more, and with solids contents from 28 to 84% by weight, are available. Silicates with weight ratios in the range of 3-4 can react with a number of other compounds to form gels with adhesive properties. In the so-called ‘chemical grouting’ of soil and rock formations, the gel is formed within a porous soil or rock, thus blocking the pores and reducing the formation’s overall permeability and increasing its strength.
