An aqueous orthosilicate solution comprising m[SiO4.sup.4]+nX.sup.1+ in an aqueous solution wherein X is an alkali metal cation selected from the group consisting of sodium or potassium; and wherein n is four to five times greater than m. The aqueous orthosilicate solution is made by adding silicon particles of less than about 3 cm and water to a pressure vessel followed by adding a molar excess of alkali caustic to the pressure vessel containing the silicon particles. The temperature in the vessel is maintained not to exceed about 190 F. while an aqueous orthosilicate solution is formed. Upon cooling the formed aqueous orthosilicate solution is recovery. Aluminum or CuO can be added during the initial heating.

An aqueous orthosilicate solution comprising m[SiO4.sup.4]+nX.sup.1+ in an aqueous solution wherein X is an alkali metal cation selected from the group consisting of sodium or potassium; and wherein n is four to five times greater than m. The aqueous orthosilicate solution is made by adding silicon particles of less than about 3 cm and water to a pressure vessel followed by adding a molar excess of alkali caustic to the pressure vessel containing the silicon particles. The temperature in the vessel is maintained not to exceed about 190 F. while an aqueous orthosilicate solution is formed. Upon cooling the formed aqueous orthosilicate solution is recovery. Aluminum or CuO can be added during the initial heating.