Method for purifying process water or wastewater containing wood resin
CA 2095180 A1 · Owner: Andersson, Arne O.R. · Inventors: Andersson, Arne O.R.; Wretborn, Magnus J.; Goransson, Gert G.M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Wood-resin-containing process water or wastewater from the pulp industry is purified by adding as floccu-, lants, a high-molecular-weight polyethylene oxide and a water-soluble, non-ionic cellulose ether suitably having, a flocculation temperature of The added amount per litre of water is preferably 2-20 mg of the high-molecular-weight polyethylene oxide and preferably 5-30 mg of the non-ionic cellulose ether.
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 29, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 29, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 29, 2015.
- 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.