Manufacture of gypsum board from fgd gypsum
CA 1215623 A · Owner: National Gypsum Company · Inventors: Burkard, Edward A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
By-product gypsum which is formed during a, flue gas desulfurization process (FGD gypsum) is, carefully formed as an aqueous slurry of crystals having a mean particle diameter of between about 35 microns and 80 microns and filtered, which filter cake is substantially completely dried before calcination without any substantial grinding action the crystals, are then flash calcined to a hemihydrate then ground, to reduce consistency, and then formed into an aqueous slurry from which a paper-covered gypsum board is formed of superior core quality.
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
- Granted December 23, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 23, 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.