Report of Investigations 9181: Leaching Gold-Silver Ores with Sodium Cyanide and Thiourea under Comparable Conditions

Details

• Personal Author:
  Eisele, Judith A. ; Hunt, Al H. ; Lampshire, Dan L.
• Corporate Authors:
  United States. Bureau of Mines
• Description:
  There is currently much interest in how extraction of gold and silver from ores with acidic thiourea solution compares with extraction using alkaline cyanide solution. Agitation leaching tests were performed by the Bureau of Mines on 14 precious metal ores using sodium cyanide (NaCN) and thiourea [(NH2)2CS] as extractants. The objective was to compare the results of the two extractants. NaCN was used at a concentration of 2 g/l with and without H2O2 as an oxidant. (NH2)2CS was used at concentrations of 2 and 20 g/l, and the solution potential was controlled at 390 to 420 mv standard hydrogen electrode (eh) with Fe2(SO4)3. With both reagents at 2-g/l extractant levels, NaCN extracted more gold and silver than (NH2)2CS from all of the ores. At 20 g/l (NH2)2CS compared with 2 g/l NaCN, (NH2)2CS extracted more gold than NaCN from two ores, the same amount from one ore, and more silver from one ore. NaCN extracted more gold than (NH2)2CS from 10 ores and more silver from 4 ores. [Description provided by NIOSH]
• Subjects:
  Cyanides Occupational Health Safety Solvents Thiourea
• Keywords:
  Gold Hydrogen-peroxide Leaching Ore-processing PH-values Redox-potential Silver Solvent-extraction
• Series:
  Mining Publications
• Subseries:
  Report of Investigations
• ISSN:
  1066-5552 (print)
• Publisher:
  United States. Bureau of Mines
• Document Type:
  Text
• Genre:
  Case Report
• Place as Subject:
  Nevada ; OSHA Region 9
• Rights:
  Public Domain
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  RERC - Reno Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  13 pdf pages
• NIOSHTIC Number:
  nn:10006177
• NTIS Accession Number:
  PB89-104046
• Citation:
  Reno, NV: U.S. Department of the Interior, Bureau of Mines, RI 9181, 1988 Jan; :1-7
• Federal Fiscal Year:
  1988
• Peer Reviewed:
  False
• Source Full Name:
  Reno, NV: U.S. Department of the Interior, Bureau of Mines, RI 9181
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a6133d2893b2ceb98e7960c4d6e3236b88cab44cbcc98576d3b9f44f76f945ff3d8fa2c0a74fe5d7416afe2a17a9e4f004d4a9817234bd17b9b0c8448b7689c6
• Download URL:
  https://stacks.cdc.gov/view/cdc/201777/cdc_201777_DS1.pdf
• File Type:
  [PDF - 272.66 KB ]