Recovery of Au and Ag from the roasted calcine of a copper-rich pyritic refractory gold ore using ion exchange resins

Albert MSUMANGE D., Yener YAZICI E. Y., CELEP O., DEVECİ H., KRITSKII A., KARIMOV K.

MINERALS ENGINEERING, cilt.195, 2023 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 195
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1016/j.mineng.2023.108017
  • Dergi Adı: MINERALS ENGINEERING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, Compendex, INSPEC, Metadex, Veterinary Science Database, Civil Engineering Abstracts
  • Anahtar Kelimeler: Refractory Gold Ore, Copper, Cyanide Leaching, CIL, CIP, Resin, RIL, RIP, ACTIVATED CARBON, CYANIDE, ADSORPTION, KINETICS, ABSORPTION, EXTRACTION, SILVER
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

The recovery of Au and Ag from a roasted copper-rich pyritic refractory gold ore (78 g/t Au, 6.8 g/t Ag, 1.38 % Cu and 3.09 % Fe was investigated. Cyanide leaching and adsorption tests were performed at different concentrations of cyanide (1.5 g/L and 5 g/L NaCN) and the adsorbent dosages ranged from 2 g/L to 10 g/L. In the cyanide leaching tests, those performed at a high cyanide level (i.e., 5 g/L) produced high gold and silver extractions from the roasted ore apparently due to the increased availability of cyanide for gold leaching. Adsorption tests (CIL/CIP, RIL/RIP) were performed to investigate the selective recovery of gold and silver from copper-laden pregnant leach solutions obtained from cyanide leaching of the roasted ore. Activated carbon (NORIT GAC 1240), strong base resin (Purogold A194) and weak base resin (Purogold S992) were tested as adsorbents in these tests. The practical importance of increasing cyanide concentration on the selectivity (gold/ silver vs copper) of resins as well as activated carbon was demonstrated. Each adsorbent offered good selectivity for gold over copper, particularly at a high concentration of cyanide (5 g/L NaCN). Purogold S992 appeared to be the most selective adsorbent with the highest gold and the lowest copper loadings. This distinctive trait makes the resin preferable for gold recovery from cyanide solutions containing significant levels of copper. Comparative pore size distribution analysis of the adsorbents has shown that Purogold S992 has the smallest pores with uniform size distribution among the adsorbents used. This was concomitant with its superior selectivity for gold at high cyanide concentration, which is linked with the small-size and linear gold-cyanide complexes c.f. large size and non-linear copper-cyanide complexes (Cu(CN)32- and Cu(CN)43-).