Separation of heavy metals from waste water of the titanium dioxide industry
CA 2079627 C · Owner: Kronos, Inc. · Inventors: Schinkitz, Dieter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
For economical and assured separation of chromium vanadium and titanium, ions from acidic waste waters which accrue in great quantities in preparation of, titanium dioxide, the pH is first raised to around a value of 3 by addition of a, calcium and magnesium compound, preferably through addition of dolomite brick powder. Directly thereafter, the pH is fine tuned into the range of 4.3 to 4.7 through addition of calcium hydroxide and/or sodium hydroxide and the , hydroxides, are separated with the aid of a flocculating agent. Since iron ions and calcium ions, remain mainly dissolved in the waste water through such selective precipitation, only a relatively small volume of slush has to be …
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 October 1, 1992 and granted January 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 1, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 1, 2014.
- 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.