Sodium metasilicate anhydrous and sodium metasilicate pentahydrate are also known as types of sodium silicate, liquid glass or water glass.ulp and Paper. One principal use of sodium metasilicate is in the pulp and paper industry. It is used in sizing and coating paper. It is also used, coupled with hydrogen peroxide, in the cellulose bleaching process, in which it acts as a buffer and stabilizing agent.