Electro-hydrometallurgical chloride process for selective gold recovery from refractory telluride gold ores: A mini-pilot study

Ivan Korolev, Pelin Altinkaya, Mika Haapalainen, Eero Kolehmainen, Kirsi Yliniemi, Mari Lundström*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

11 Citations (Scopus)
226 Downloads (Pure)

Abstract

The current paper introduces for the very first time recently invented electrodeposition-redox replacement (EDRR) method in continuous leaching-recovery-solution purification process. The mini-pilot study reveals that longer duration of the EDRR process is beneficial as it increases gold recovery per stage and decreases the specific energy consumption of the EDRR. This extraordinary behavior is postulated to be inherent to the EDRR process, as during the EDRR the cathode surface is gradually transformed from stainless steel surface to gold(±copper) surface, thus increasing process performance with time. In addition, gold concentration of 1 mg/L in the PLS was established as the minimum concentration required for efficient operation of the EDRR process. Gold extraction from ore to solution throughout the pilot test reached up to ca. 90%, whereas in reference cyanidation test only 64% of gold was dissolved. Overall, after 150 h of pilot experiment, 83% of dissolved gold was recovered from solution on the cathode, resulting in 68.5% holistic recovery of gold from ore. Furthermore, process simulation model was built, and it suggested that closed-loop operation of cupric chloride leaching – EDRR recovery – copper precipitation process can recover in total over 84% of gold from refractory telluride ore to the cathode product, providing further evidence of true potential of EDRR in sustainable gold extraction.

Original languageEnglish
Article number132283
Number of pages11
JournalChemical Engineering Journal
Volume429
Early online date8 Sept 2021
DOIs
Publication statusPublished - 1 Feb 2022
MoE publication typeA1 Journal article-refereed

Keywords

  • Pilot plant
  • Cyanide-free leaching
  • electrodeposition-redox replacement
  • EDRR
  • HSC Chemistry

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