Patents Assigned to Envirochip Technologies Ltd.
  • Patent number: 5188713
    Abstract: A process for recovery of metal from a feedstock comprising copper is provided. The process comprises the steps of:(a) contacting the feedstock with an aqueous mixture comprising ammonium nitrate having a concentration greater than about 1.5M and sulphuric acid having a concentration greater than about 6M at a temperature of from about 105.degree. C. to about 130.degree. C., to produce a first residue comprising a cuprous salt and a leachate comprising copper;(b) separating the residue from the leachate; and(c) electrowinning copper from the leachate.The process may also be used advantageously to recover iron present in the feedstock in a form other than jarosite.
    Type: Grant
    Filed: March 5, 1991
    Date of Patent: February 23, 1993
    Assignee: Envirochip Technologies Ltd.
    Inventors: Robert N. O'Brien, Thomas D. McEwan