Method for adsorbing and separating heavy metal elements by using a tannin adsorbent and method of regenerating the adsorbent
CA 2075790 C · Owner: Kamei, Yoshinobu · Inventors: Kamei, Yoshinobu; Shirato, Wataru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of adsorbing and separating a heavy metal element by using an insoluble tannin or a gelled tannin adsorbent comprising: (a) adjusting the pH of a solution containing a plurality of heavy metal elements to a predetermined pH;, (b) contacting the adsorbent with the solution in which the pH thereof is adjusted;, (c) adjusting the pH of the solution contacted with the adsorbent to a pH different from the predetermined pH of step (a); and (d) contacting the solution in which the pH thereof is adjusted at step (c) with the adsorbent prepared at step (b). According to the inventive method all of the heavy metal elements can be efficiently separated and adsorbed by using a tannin adsorbent …
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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 August 11, 1992 and granted May 18, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 11, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 11, 2014.
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