Hydrometallurgical treatment for the purification of waelz oxides through lixiviation with sodium carbonate
CA 2192084 C · Owner: Compania Industrial Asua-Erandio, S.A. (Aser, S.A.) · Inventors: Danobeitia Sierra, Iker; Goicoechea Gandiaga, Nestor; Vallejo Ochoa De Alda, Javier
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This process allows the elimination of contaminants from waelz oxide, (chlorine, sodium, potassium sulfur and, fluorine, fundamentally), by means of its hydrometallurgic treatment in the following stages, - Leaching with sodium carbonate in warm aqueous alkaline medium. - Solid - liquid separation of the effluent and the solid material. - Purification of the effluent by the elimination of the heavy metals, and optionally, the undesired anions. - Washing with water of the solid material obtained after-the sodium leaching. - Solid - liquid separation of the water and the purified waelz oxide. - Recirculation and warming of the effluent obtained from the washing stage, for its reutilization in …
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
- Filed April 10, 1996 and granted June 26, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 10, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 10, 2018.
- 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.