A process for the preparation of amorphous silica
CA 2398303 A1 · Owner: Samuel, Joshua · Inventors: Samuel, Joshua
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides a process for the production of amorphous silica from a silica-based material having a silica content of at least 90% comprising: a) heating said silica-based material with CaCl2 at a temperature in the range , of about 900~C to about 1,200~C and in the presence of water vapor in excess of the stoichiometric amount needed for the reaction: x CaCl2 + y SiO2 + x H2O .fwdarw. (CaO)x .bullet. (SiO2)y + 2x HCl wherein x is equal to or greater than y to obtain a conversion of said silica-based material to calcium silicates in excess of 99.9%; b) Leaching said calcium silicates with HCl to form a solution of CaCl2 with insoluble silica; c) separating said insoluble …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed January 15, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 15, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 15, 2023.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.