August 2021
Volume 73    Issue 8

Optimization process of refractory gold ore extraction by hypochlorite oxidative leaching

Anuar, Wan Nur Syafiqah; Ardani, Mohammad Rezaei; Baharun, Norlia; Ismail, Suhaina; Rahman, Shaik Abdul

ABSTRACT:

Refractory gold ore contains sulfide minerals like pyrite, chalcopyrite and sphalerite that are difficult to be directly leached by cyanidation or by lixiviants such as thiourea and halides. In such cases, it is necessary to perform oxidative pretreatment of the ore to oxidize the sulfide matrix, and gold particles can be exposed to the solution during the leaching process [1]. In recent years, hypochlorite and chloride solutions have been introduced as alternative materials for hydrometallurgical methods of gold extraction instead of cyanide solution [2]. A previous study by Hasab et al. [3] reported that the gold dissolution rate in hypochlorite solution was higher than in the cyanidation process, due to the presence of hypochlorous acid (HOCl) as a strong oxidizing agent. In a hypochlorite leaching system, the change in pH can influence the presence of oxidant species in the solution: the hypochlorite ion (OCl−) is stable in pH greater than 7.5, HOCl can be found in pH between 4.0 and 7.5, and aqueous chlorine (Cl2 (aq)) is the predominant oxidant when pH is below 4.0. As HOCl is the most effective oxidizing agent for gold extraction, pH should be maintained in the range of HOCl stability [4].

 

Full-text paper:
Mining, Metallurgy & Exploration (2021) 38:1191–1201, https://doi.org/10.1007/s42461-020-00376-6
 

HOW CAN YOU READ THE FULL TEXT OF MME PAPERS?

Follow these easy steps if you are an SME member:
  • Go to www.smenet.org/login . Sign in with your email address and password.
  • Hover your mouse over “Publications and Resources” in the top banner. Click on “Mining, Metallurgy & Exploration (MME) Journal” in the pull-down menu.
  • Scroll down and click on the “Read the MME Journal Online” button, which will take you to the Springer site as an SME member who is eligible for free access. (To see published papers on the Springer site, click on “Browse Volumes & Issues” in the blue banner.)
If you are not an SME member, go to https://www.springer.com/engineering/journal/42461 for paid access. Or join SME at www.smenet.org/join