Process for the regeneration of sodium hydroxide from sodium sulfide
CA 2174674 C · Owner: Myers, Ronald Damian · Inventors: Myers, Ronald Damian; Brons, Glen Barry
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is directed toward a process for regenerating sodium hydroxide (NaOH) from aqueous solutions of sodium sulfide (Na2S) comprising heating aqueous sodium sulfide in the presence of a metal selected from the group consisting of iron and cobalt, for a time and at a temperature sufficient to form a metal sulfide, sodium hydroxide and molecular hydrogen.
Read the whole patent
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 April 17, 1996 and granted July 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 17, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 17, 2018.
- 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
Timeline From CIPO dates
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.