Leaching and recovery of gold using ammoniacal thiosulfate leach liquors (a review)

“Turn-on” Fluorescence Detection of Lead Ions Based on Accelerated Leaching of Gold Nanoparticles on the Surface of Graphene

“…21,40 And the complexes formed a dense passive layer on the surface of AuNPs in the presence of dissolved oxygen (eq 1), 21,25 resulting in slight decrease of the size of AuNPs on the surface of graphene, as shown in Figure 1B, E (diameter about 79 ± 35 nm (70%)).…”

“…Usually the complexes were reported as Au(S 2 O 3 ) 2 3− . 21 After adding Pb 2+ and 2-ME, the AuNPs could rapidly be dissolved to form Au(2-ME) 2 − complexes in solution. As a result, the fluorescence of the G-Au NCs increased owing to the gradual dissolution of AuNPs.…”

“…19,21,41 Fortunately, alkanethiols, such as 2-mercaptoethanol (2-ME), were strong etching agents because of the high Au−S band energy (184 kJ/mol). 25 25,40 However, if there was only 2-ME, i.e.…”

Comparative Study on the Adsorption of [AuCl₄]^– onto Salicylic Acid and Gallic Acid Modified Magnetite Particles

“…This is why many researchers give great attention for the recovery of gold over the years. Methods which have been applied to the recovery of gold from its solutions include, chelating resins [2], ammoniacal thiosulfate leach liquors [3], and ion exchange [4].…”

Enhanced leachability of gold and silver in cyanide media: Effect of alkaline pre-treatment of jarosite minerals

“…Cyanide leaching is predominantly used to extract gold from the gold ores. Recently, concerns about cyanide toxicity (Adams, 1998), its relatively slow reaction kinetics and lack of selectivity has prompted researchers to seek alternative lixiviants such as thiourea, thiosulfate and aqua regia (Jackson, 1986;Habashi, 1986;Grosse et al, 2003). Notwithstanding the efficacy of the above lixiviants, cyanidation of gold is still the most elegant technique available for gold dissolution on the basis of production efficiency and reaction kinetics (Prasad et al, 1991).…”