Patents by Inventor Shitang Tong

Shitang Tong has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for the production of alpha hemihydrate calcium sulfate from flue gas sludge
    Patent number: 5562892
    Abstract: Process for producing alpha-hemihydrate calcium sulfate from FGD sludge comprising treating an aqueous slurry of the sludge with a stabilizing effective amount of a stabilizing polyhydric alcohol to stabilize the .alpha.HH to obtain .alpha.HH crystal growth, at atmospheric pressure and a temperature greater than 80.degree. C. and a pH selected from 3 to 6. The polyhydric alcohol may be selected from ethylene glycol, glycerol and a carbohydrate. The process offers a commercially viable method of making .alpha.HH from FGD sludge wastes.
    Type: Grant
    Filed: January 26, 1995
    Date of Patent: October 8, 1996
    Inventors: Donald W. Kirk, Shitang Tong