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Expired Canadian patentCanada

Process for removing sulfur from coal

CA 1094481 A · Owner: Atlantic Richfield Company · Inventors: Burk, Emmett H. Jr.; Yoo, Jin S.; Karch, John A.

CIPO record

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Abstract From the Canadian patent

A process for reducing the pyritic sulfur content of coal comprising:, 1) contacting coal particles with an aqueous solution of iron complexing agent, and an oxidant; and;, 2) recovering coal particles of reduced sulfur content.

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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 January 27, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 27, 1998.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 28, 1977
GrantedJanuary 27, 1981
Term endedJanuary 27, 1998
Patent numberCA 1094481 A
Classification (IPC)C10L9/02

Timeline

Timeline From CIPO dates

1978198119841987199019931996Application filedJuly 28, 1977Patent grantedJan 27, 1981Term endedJan 27, 1998

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.