Cementitious encapsulation of waste materials and/or contaminated soils containing heavy metals, to render them immobile
CA 2107971 C · Owner: Stark, J. Norman · Inventors: Stark, J. Norman
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to the treatment of toxic wastes, and particularly to the immobilization of metals, in toxic amounts, in such wastes. A waste product comprising the metals is provided. A mixture is prepared comprising said toxic wastes, water, and a cementitious composition. The cementitious composition comprises magnesium oxide and magnesium chloride in proportions effective to produce, with said water, a magnesium oxychloride cement. The cementitious composition is present in an amount, which on setting is effective to, immobilize the metals in said waste. The mixture of toxic waste and cementitious composition is introduced to a disposition site, and allowed to set at said …
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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 October 7, 1993 and granted June 3, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 7, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 7, 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.