In the process of hardening soil, Sodium Silicate is used as follows:

1.It hardens the soil surface as needed to prevent excessive water loss.
2.It seals the pores of concrete or brick, often used in underground construction.

          In this process, sodium silicate is injected into the soil along with calcium chloride. The combination forms a water-insoluble gel that seals the soil pores, strengthening the soil and preventing water leakage.