Kraft pulping process
CA 2256923 A1 · Owner: Eco-Tec Limited · Inventors: Sheedy, Michael A.; Brown, Craig J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improvement in a conventional Kraft pulping process in which dust is collected from exhaust gases produced in the black liquor recovery cycle and is dissolved in water to produce a solution containing sodium chloride and sodium sulfate. The solution is filtered to yield a solid product and a filtrate solution. The filtrate solution is fed to an ion exchange, unit which removes chloride and produces a purified sodium sulfate product. The sodium chloride is removed from the ion exchange resin by water elusion, and useful recovered chemicals are recycled to the recovery cycle of the Kraft process. In one embodiment, only a portion of the dust is dissolved so that the solid product produced …
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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 December 23, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 23, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 23, 2020.
- 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.