Abstract: An aqueous orthosilicate solution comprising m[SiO44?]+nX1+ 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.