Process for removal of suspended solids from pulp and paper mill effluents
CA 2102882 C · Owner: Dorica, Joseph · Inventors: Ramamurthy, Pritham; Dorica, Joseph; Prahacs, Steven
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is presented for removal of suspended solids including resin and fatty acids from pulp mill effluents including Chemi-Thermo-Mechanical Pulp (CTMP) mill and deinking effluents. The process involves filtration of untreated or primary treated effluents through a mat of primary sludge pulp or woodroom sludge. A sludge mat is formed on a belt or drum filter wire screen or punched drum and the effluent to be treated is filtered through the mat. Most of the suspended solids and a part of colloidal material and dissolved solids are retained by the mat. Following the filtration stage the sludge is dewatered and removed. A portion of the sludge is recycled to form the mat for the next …
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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 November 10, 1993 and granted July 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 10, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 10, 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
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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.