Abstract
In this study, potassium ferrocyanide, a nontoxic cyanide precursor in dark and diffuse reflection environment, was applied as reagent for the leaching of gold. The free cyanide ions could gradually release from potassium ferrocyanide solution under the ultraviolet light. Orthogonal leaching experiments were performed in gold ore to analyze the effect of solution pH, potassium ferrocyanide dosage, and temperature in a potassium ferrocyanide solution system under UV light. Response surface methodology (RSM) was applied to explore the role of potassium ferrocyanide in gold leaching; optimized results showed that the gold recovery reached 67.74% in a high-alkaline environment at a 12.6 pH, 3.8 kg/t potassium ferrocyanide dosage, 62 °C, and irradiance of 10 mW·cm−2. The gold leaching kinetics were monitored by quartz crystal microbalance with dissipation (QCM-D) of potassium ferrocyanide solution. The results indicate that the gold extraction process could be divided into two stages: adsorption and leaching, and a rigid adsorption layer formed on the reaction surface. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis of the gold sensor surface after leaching reaction showed that –C≡N appears on the gold sensor surface, and the gold is oxidized to form AuCN complexes.
Highlights
This paper provides a novel hydrometallurgical method for gold extraction with potassium ferrocyanide (PF) solution irradiated by UV light
Irradiation time, the first experiment was by inte com
In as order investigate the dependence of a free cyanide ion decomposition onout thethe ness coat for the quartz crystals and nm chromium coatcarried placed in the oftime, PF the solution at 0–100 mmol/L
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. With this limitation in mind, a nontoxic cyanide precursor, potassium ferrocyanide (PF), has been investigated It could release free cyanide ions under the ultraviolet light but have the high stability of ferrous cyanide complex in diffuse light or in the darkness (acute toxicity test, LD50 = 1600–3200 mg/kg) [11]. LA Betancourt-Buitrago [16] described a method of complexed cyanide recovery from synthetic mining wastewater by means of anoxic photocatalytic treatment using TiO2 and scavengers. It inspired us to apply free cyanide ions released by PF solution to extract gold from gold ore It could make reutilization of ferrous cyanide complex in wastewater and avoid the highly toxic dangers of cyanide in transport and preservation. This paper provides a novel hydrometallurgical method for gold extraction with PF solution irradiated by UV light
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
