Patents Represented by Law Firm Pennis & Edmonds LLP
  • Patent number: 5942024
    Abstract: A method comprising the steps of solvent extracting a gold bearing chlorination leach solution with DBC, scrubbing the resulting gold bearing organic phase with hydrochloric acid and reducing gold is capable of recovering gold in high purity by:(1) adjusting the concentration of hydrochloric acid in the gold bearing chlorination leach solution to 0.5-1.75 N before the solvent extraction and then scrubbing the resulting gold bearing organic phase with 0.25-0.75 N hydrochloric acid; and/or(2) performing five-stage scrubbing with hydrochloric acid by either one of the following three approaches: i) after three-stage scrubbing, centrifugal separation is effected and separation is then performed by filtration with a filter having an opening size of 0.05-5 .mu.m, with the resulting organic phase being then subjected to two-stage scrubbing; ii) after five-stage scrubbing, centrifugal separation is effected and separation is then performed by filtration with a filter having an opening size of 0.05-5 .mu.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: August 24, 1999
    Assignee: Nippon Mining & Metals Co., Ltd
    Inventors: Abe Yoshifumi, Inomata Takehiko