Patent ID: 7622097

Claim:
A method for hydrothermal production of an aqueous sodium silicate solution having a SiO 2 :Na 2 O molar ratio of at least 3.0:1, said method comprising the steps of: (i) manufacturing titanium dioxide, wherein the manufacturing comprises generating a waste product, the waste product comprising a precursor solid silica source; (ii) collecting the waste product; (iii) exfoliating and removing titanium dioxide particles adhering to the surface of the precursor solid silica source of the collected waste product, to form cleaned silica; (iv) producing an intermediate sodium silicate solution by a hydrothermal fusion reaction of the cleaned silica with a caustic soda in an autoclave; (v) forming an amorphous silica source by transposing the SiO 2 content of the intermediate sodium silicate of step (iv) by a separate precipitation process; and (vi) dissolving the amorphous silica provided in step (v) in the intermediate sodium silicate solution of step (iv) and raising the SiO 2 :Na 2 O molar ratio to result in a high modulus sodium silicate solution.