Kinetic Investigation and Dissolution Behavior of Cyanide Alternative Gold Leaching Reagents

Birich, Alexander; Stopić, Srečko; Friedrich, Bernd

doi:10.1038/s41598-019-43383-4

Cited by 66 publications

(48 citation statements)

References 40 publications

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“…In previous decades, the extraction of gold was performed from gold ores by using cyanide leaching [42,43]. Due to the environmental issues of cyanide, of halides, aqua regia, thiosulfate and thiourea are now used as alternative materials [44].…”

Section: Introductionmentioning

confidence: 99%

Low-cost synthesis of AuNPs through ultrasonic spray pyrolysis

Tiyyagura

Majerič

Anžel

et al. 2020

Mater. Res. Express

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The present research informs about the synthesis of gold nanoparticles (AuNPs) through Ultrasonic Spray Pyrolysis (USP), which were collected in ethanol with 0.1% Polyvinylpyrrolidone (PVP). Initially, the research focused on two precursors, where the first represented a homemade H-HAuCl 4 , completed in our own laboratory through the chlorine gas method by using HCl and KMnO 4 , and the second was the commercial C-HAuCl 4 , prepared by using Gold (III) chloride tetrahydrate powder and deionised water. The goal was to find any potential precursor differences and their influences on the later use for AuNPs synthesis through USP using almost the same parameters. In the first step of research it was determined that the H-HAuCl 4 precursor was similar to C-HAuCl 4 in chemical composition, surface tension and pH value. This finding represented the starting point for being able to use H-HAuCl 4 in the USP for AuNPs' synthesis. In the second step, AuNPs were synthesised from both types of precursors. Afterwards, characterisation of some functional properties by FTIR and UVvis techniques was done directly for H-and C-AuNPs in the collecting media. For SEM/EDX and TEM microscopy both types of H-and C-AuNPs were dried, and observation revealed that the morphology, shape and size distribution of dried AuNPs were very similar. Based on the performed laboratory research, it could be concluded that prepared H-AuNPs could represent a new and lowcost effective solution for future USP transfer onto the industrial level, not only in in the process itself, but also in the field of Low-cost Precursor Preparation.Abbreviations

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Section: Introductionmentioning

confidence: 99%

Low-cost synthesis of AuNPs through ultrasonic spray pyrolysis

Tiyyagura

Majerič

Anžel

et al. 2020

Mater. Res. Express

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“…Metals 2020, 10, x FOR PEER REVIEW 2 of 9 investigated in terms of leaching mechanism and kinetics [14][15][16][17]. Lampinen et al investigated the ammoniacal thiosulfate leaching of pressure oxidized sulfide gold concentrate [18].…”

Section: Methodsmentioning

confidence: 99%

“…Aylmore and Muir conducted a thermodynamic analysis to provide a range of pH and Eh conditions for reagent concentrations [13]. In addition, the thiosulfate leaching process for Au extraction has 2 of 9 been investigated in terms of leaching mechanism and kinetics [14][15][16][17]. Lampinen et al investigated the ammoniacal thiosulfate leaching of pressure oxidized sulfide gold concentrate [18].…”

Section: Introductionmentioning

confidence: 99%

Leaching Behavior of Gold and Silver from Concentrated Sulfide Ore Using Ammonium Thiosulfate

Bae

Kim

Sohn

et al. 2020

Metals

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Ammonium thiosulfate is an alternative lixiviant for the hydrometallurgical treatment of sulfide gold ores. The present study is primarily focused on ammonium thiosulfate leaching of gold (Au) and silver (Ag) from the sulfide ore (Sunshin mine in Korea). The main chemical composition of the concentrate was Au (84 ppm), Ag (852 ppm), Fe (18.9%), Si (23.2%), and S (21.1%). The effects of various parameters on the process, such as leaching time (1–4 h), ammonium thiosulfate concentration (0.05–0.5 M), copper sulfate (CuSO4), concentration (0.05–0.25 M), solid to liquid ratio (0.2–0.5), and reaction temperature (40–60 °C) were systematically examined. Optimum Au leaching efficiency (>99%) was obtained under the following leaching conditions: 0.5 M ammonium thiosulfate with 0.05 M CuSO4 concentration, 0.2 S/L ratio at 60 °C for 2 h. The results indicate that the behavior of Ag was similar to that of Au. Almost complete dissolution of Ag occurred under following leaching conditions: 0.5 M ammonium thiosulfate with 0.05 M CuSO4 concentration at 60 °C for 4 h. This study would be useful in understanding the eco-friendly leaching systems of Au and Ag during the hydrometallurgical process of sulfide gold ore.

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“…The recovery process of precious metal is divided into two steps: firstly, dissolve PM 0 into PM x+ from electronic wastes; then reduce PM x+ to PM 0 from the leachate. In the process of dissolving PM 0 to PM x+ , dissolution methods in the industry involving the use of corrosive and toxic aqua regia and cyanidation endanger the environment and characterized of high chemical consumption [14][15][16][17][18] . In view of the toxicity of aqua regia and cyanide, scientists have developed non-toxic leaching agents such as thiourea, thiosulfate and iodine to treat the dissolution of gold, but they are ineffective for the dissolution of platinum group precious metals and the operation steps are complicated (Extended Data Table 1) [18][19][20][21][22][23] .…”

Section: Introductionmentioning

confidence: 99%

Selective recovery of precious metals through photocatalysis

et al. 2021

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Precious metals such as gold and platinum are valued materials for a variety of important applications, but their scarcity poses a risk of supply interruption. However, the dissolution and recovery of precious metals using the current methods are limited by associated serious environmental pollution and high energy consumption. Here, we show a photocatalytic process that allows one to selective retrieve 7 kinds of precious metal elements (Ag, Au, Pd, Pt, Ru, Rh and Ir) (with dissolution efficiency of 99%) from waste circuit boards, ternary automotive catalysts and even ores. Precious metals is recovered with high purity (≥98%) through a simple reductive method. The whole process only needs light and catalyst without strong acid, strong base and highly toxic cyanide. It has an environmentally friendly, scalable and efficient way, in which the catalyst has been recycled more than 100 times under normal temperature and pressure without performance degradation. It has successfully realized the scale of dissolution from grams to kilograms, and it is expected to realize large-scale recovery of precious metals in industrial application. This general approach provides an unprecedent technology for recycling resources on earth.

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Kinetic Investigation and Dissolution Behavior of Cyanide Alternative Gold Leaching Reagents

Cited by 66 publications

References 40 publications

Low-cost synthesis of AuNPs through ultrasonic spray pyrolysis

Low-cost synthesis of AuNPs through ultrasonic spray pyrolysis

Leaching Behavior of Gold and Silver from Concentrated Sulfide Ore Using Ammonium Thiosulfate

Selective recovery of precious metals through photocatalysis

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