Kraft pulping process
CA 1205960 A · Owner: St. Regis Corporation · Inventors: Steltenkamp, Michael S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process of producing cooking liquor for addition to a digester for enhancement of the yield derived from kraft pulping of wood chips in which a portion of the black liquor is treated with lime under certain conditions and then reused as cooking liquor. The causticizing of the black liquor results in the generation of polysulfide ions and allows through the, formation of calcium-organo complexes for the carryover of, soluble calcium with the black liquor. The presence of calcium ions synergistically enhances the effectiveness of polysulfide such that the use of the new cooking liquor results in pulp yield increases of several percentage points for the same lignin content when compared to …
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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
- Granted June 17, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 17, 2003.
- 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.