Gold recovery by iodine-iodide solution is an effective and environment-friendly method. The aim of this research is to investigate the possibility of iodine-iodide gold recovery from gold-plated metal, which is a waste product of the electronic industry. Leaching experiments were carried out in solutions, containing 25 g l-1 iodine and 100 g l-1 KI, …

For the solution of initially 0.1 M iodide and 10 mM iodine, substituting the equilibrium concentrations of iodide, tri-iodide and soluble gold iodide AuIy species as 90, 7.25 and 4.8 mM respectively to the Nernst equations, eqs. (3) and (4), yield both El and E2 values of 0.565 V versus SHE.

In contrast, gold extraction from the oxide ore in a solution containing 20 g/L iodide and 4 g/L iodine reached 77% in 6 h and 89% in 24 h. With iodate as the oxidant, no gold could be leached in ...

Aqua regia and iodine/iodide leaching systems were the most successful reagents, yielding of gold while showing very fast leaching rates. A comparison …

The main disadvantage of iodine-iodide leaching is the great consumption of reagents and the need for a significant number of filtrations. Keywords: gold, iodine-iodide lixiviantsolution, leaching ...

Iodine-Iodide Leaching. The pregnant leach solution with an initial pH of 2.84 and Eh of 0.58, V derived from the iodine-iodide leaching under the previously specified conditions contains precious metals such as Au, Ag and Pd in appropriate amounts, and some other base metal impurities like Ca, Cu, Al, Pb, Mg, Zn, Fe etc. in …

McGrew proposed the use of an I- containing electrolyte to leach gold ores. An iodine lixiviant is added to an ore containing iodine reducing components. As iodide …

The results show that the initial iodine concentration has a significant effect on gold leaching, and increasing the initial iodine concentration was beneficial to gold …

2.2.2. Iodine-Iodide Leaching The experiments for gold leaching from the WPCBs ash sample in iodine-iodide solutions were conducted in a 0.5 L baffled volumetric flask immersed in a thermostatically controlled water bath. Agitation was done by a flat blade impeller. Effects of various important variables such as iodine/iodide concentration, pulp

The iodine-assisted heap leaching of chalcopyrite involves the addition of iodide in ferric sulfate media to accelerate the dissolution of chalcopyrite at ambient temperature. The previous studies using reactor leaching tests identified the solution potential, the amount of iodide added, and temperature as the factors controlling the …

Widely used cyanide leaching (a) is environmentally burdensome and toxic. More than stoichiometric amounts of moderately toxic iodine are needed for quantitative dissolution of gold in water (b, iodine–iodide leaching) or in organic solvents (c), which makes these methods less affordable.

Small amounts of iodide, iodine, or other iodine compounds in thiocyanate leaching have been reported to increase the dissolution rate to a level comparable with those obtained at higher ...

In the iodine–iodide leaching process, the appropriate parameter such as leaching time, iodine-to-iodide ratio, S/L, and pH was important for obtaining high dissolution efficiency of Au, Ag, and Pd from (SCWO + HL)-treated PCBs of mobile phone. The optimum iodine/iodide ratio determined the oxidizing and complexation ability for …

Non-cyanide Leaching Processes in Gold Hydrometallurgy and Iodine-Iodide Applications: A Review. ... However, leaching by cyanide solutions has a set of substantial drawbacks: process duration, high cost of the reagent, nonadaptability of "stubborn" ores and concentrates, absence of possible regeneration of cyanide solutions …

Iodine leach makes most sense as it mostly ignores the trash metals, and is recyclable.However, according to the research done by the patent filers, iodide AND iodine must be present for it to work effectively. 2:1 ratio of iodide to iodine. There are about a dozen or more papers done on this leaching going back to the early 1900's.

The thermodynamic equilibria and kinetic aspect of gold dissolution in iodine–iodide leaching were studied with emphasis on the effects of pH value and …

According to other researchers, a gold leaching yield > 90% should be achievable in iodine-iodide solvent [22, 50]. The low gold recovery can be explained by the consumption of iodide ions by ...

Among them, an iodine-iodide solution is a highly selective and efficient leaching agent for the recovery of gold from gold ores and WPCBs [21,[23] [24] [25]. Several decades ago, the first ...

The authors of this study have recently applied pressure leaching with iodide to refractory gold ores, a technique developed as a noncyanide process for refractory gold ores. This new process is a one stage operation, where the oxidation of sulfide and the dissolution of gold are completed in an autoclave within 2-4 hours.

Widely used cyanide leaching (a) is environmentally burdensome and toxic. More than stoichiometric amounts of moderately toxic iodine are needed for quantitative …

Iodine–iodide leaching is a green non-cyanide gold extraction method (Zhang et al., 2012). Compared with cyanide, iodine and its compounds are nontoxic, …

To reveal the influences on iodine leaching from soil to groundwater, batch experiments were designed to investigate the kinetics of iodine migration. In detail, each soil ... It was observed that the injection of oxygen-rich water significantly reduced iodide leaching, with the higher DO concentration (8.0 mg/L) exhibiting a faster oxidative ...

Iodine-iodide leaching and activated carbon adsorption processes for recovery of gold (Au) from waste printed circuit boards (WPCBs) were discussed in this paper. A pressure oxidative acid …

The leaching kinetics of an oxide gold ore with iodide/iodine solutions. Hydrometallurgy 113–114, 42–50 (2012). Article Google Scholar

In contrast, gold extraction from the oxide ore in a solution containing 20 g/L iodide and 4 g/L iodine reached 77% in 6 h and 89% in 24 h. With iodate as the oxidant, no gold could be leached in ...

Platinum black dissolution rates were found to be dependent on added iodine content, with higher concentrations accelerating the reaction. Platinum recovery from leached materials, as determined by aqua regia digestion, was found to be 98.7% and 96.7% for untested and end-of-life PEMFCs, respectively.

H 2 SO 4) leaching was evaluated with the com parison of iodine–iodide (I–KI–H 2 O) leaching. The The experiments were carried out using 20 mM H 2 SO 4, 15 mM H 2 O 2 in the iodide solution ...

Gold extraction by iodine-iodide solution is an effective and environment-friendly method. In this study, the method using iodine-iodide for gold leaching is proved feasible through thermodynamic calculation. At the same time, experiments on flotation gold concentrates were carried out and encouraging results were obtained. Through optimizing the …

A process for the hydrometallurgical recovery of gold from materials containing gold comprising leaching the materials with a lixiviant containing iodine. To a solution concentrated with natural salts is added elemental iodine until saturated, whereupon mineral sulfides in the ore zone charged with this solution react with the iodine to form …

ABSTRACT Gold leaching in iodine-iodide solution has been intensely researched in 1980s; while due to the high cost, it has not been applied in industry. Currently, as the drawbacks of other … Expand. 19. Highly Influenced. 10 Excerpts; Save. The nature of gold-iodide adsorption onto coconut-shell carbon.