Patents by Inventor Roelof Den Hond

Roelof Den Hond 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 aluminum hydroxide from bauxite
    Patent number: 5869020
    Abstract: Process for the production of aluminium hydroxide by digesting bauxite with alkali solution and precipitating aluminium hydroxide from the digestion solution, comprising:a combining bauxite and alkali solution having a caustic concentration of at least 180 grams per liter expressed as sodium carbonate and digesting partly the bauxite in the combined product in a first digestion step at relatively low temperature,b separating reaction product obtained in step a into a liquid phase and a solids/liquid slurry,c combining liquid phase and solids/liquid slurry obtained in step b and digesting the combined product in a second digestion step at relatively high temperature,d releasing heat from the reaction product obtained in step c to preheat liquid phase obtained in step b,e separating the reaction product obtained in step d into a supersaturated sodium aluminate solution and undissolved material,f precipitating aluminium hydroxide from the supersaturated sodium aluminate solution obtained in step e and separating
    Type: Grant
    Filed: April 22, 1992
    Date of Patent: February 9, 1999
    Assignee: Shell Internationale Research Maatschappij B.V.
    Inventors: Albert Rijkeboer, Roelof Den Hond