Conventional gold mining operations rely heavily on cyanide leaching as the predominant method for recovering gold from ores and concentrates. ... Some of the experimental alternative lixiviants ...
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The glycine leaching system (i.e., an aqueous system typically consisting of glycine or one of its alkali metal salts, a pH modifier, an oxidant and sometimes, other catalysts or modifiers) has been shown effective in selectively extracting base and precious metals from various resources. Using a glycine leaching system can, therefore, be ...
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The most commonly investigated cyanide-free gold leaching options include halide, thiosulfate, and thiourea based lixiviants (Aylmore and Muir, 2001;Tran et al., 2001;Hilson and Monhemius, 2006 ...
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Over 25 alternative lixiviant processes to cyanide have been tested in the laboratory; some of which have been successful for niche applications. The process conditions, …
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Alternative lixiviants or leaching agents should also be [12]: (1) inexpensive and recyclable; (2) selective; (3) ... This paper has reviewed the most promising alternative gold leaching agents to cyanide. Although considerable research has been undertaken at a laboratory scale, most, if not all, of the alternatives identified have proven to ...
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This paper focusses on the investigation of the leaching behavior of different promising cyanide-alternative reagents and cyanide at identical conditions. In the following a brief …
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Alkaline lixiviant systems (pH > 10)include cyanide, ammonia-cyanide, ammonia, sulphide, nitriles, and a few other minor possibilities. Oxygen is the main oxidant. Cyanide, which …
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Numerous non-cyanide leaching lixiviants have been developed, among which thiosulfate is considered the most promising alternative to cyanide due to its non-toxicity, low price, high leaching rate ...
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Section snippets Survey of process parameters before the H 2 O 2 pre-oxidation trial. For a period of 5 days the ore that feeds the leaching circuit was sampled and characterized for mineralogical composition and tested for the determination of the oxygen uptake rate.In addition, measurements of dissolved oxygen (DO) and free …
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This paper has reviewed the non-cyanide gold leaching reagents with much attention being paid to the novel eco-friendly synthetic gold lixiviants (NESGLs). The NESGLs have shown a much brighter application prospect in the recovery of gold from ores compared to the traditional non-cyanide gold lixiviants and the other novel eco-friendly …
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Although gold cyanide leaching must be conducted in controlled alkaline conditions, i.e., ... gold ores, the biogenic lixiviants used, i.e., bio-cyanide, iodide-iodine, and organic acid, have the same limits as chemically generated cyanide. As a result, refractory gold ores must be pretreated via biooxidation, pressure oxidation, or roasting ...
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Gold leaching with thiourea has the advantages of fast speed (four to five times faster than that of cyanide leaching) and a high leaching rate for refractory gold ores (Choi et al., 2017, Lee et al., 2018). Thiourea is stable under acidic conditions and can form coordinating compounds with Au ions in the presence of an oxidizing agent.
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The preg-robbing phenomenon, i.e., gold precipitation back onto the gold ore or concentrate during gold leaching, in chloride as well as in cyanide media, has been known for decades (Aylmore, 2005). Almost all gold lixiviants are known to suffer from preg-robbing. However, the nature and the extent of preg-robbing and gold complex …
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Abstract. In this study, the extraction of metal-cyanide complex ions in gold-leaching, cyanide-containing wastewater by a ctylmethylammonium chloride (N263)-tributyl phosphate (TBP)- n -octanol-sulfonated kerosene system was investigated. The effects of N263 and TBP concentrations, the aqueous phase pH, and phase ratio (O/A) …
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Cyanide is currently the predominant lixiviant for gold extraction. However, cyanide is highly toxic, causing potential environmental hazards and high detoxification costs. This has …
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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 and the main thing is high toxicity of cyanide compounds. ... leaching; non-cyanide lixiviants; …
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Alkaline sulfur-containing lixiviants, including thiosulfate, polysulfides, and alkaline sulfide solutions, stand out as a promising class of alternatives to cyanide because of their low toxicity, high efficiency, and strong adaptability. In this paper, we summarized the research progress and remaining challenges in gold extraction using these noncyanide …
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Sodium Cyanide (NaCN) has been used to recover gold from gold bearing ores. This work aims to develop a simulation model of leaching process by using cyanide solvent for the dissolution of gold by ...
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It is particularly problematic for gold ores with high copper and/or high silver content as copper is often present at levels of around 1000 times the gold concentration (silver often 5-50 times gold concentration), leading to excessive cyanide consumption, and removal of available cyanide for gold leaching. Cyanide is also an expensive reagent ...
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Gold extraction from ores using non-cyanide lixiviants is currently a significant topic worldwide. Herein, we report the synthesis of an eco-friendly lixiviant that not only is much less toxic than sodium cyanide (NaCN) but also shows excellent effect in the leaching of gold. The lixiviant can be synthesized from roasting of the well-mixed …
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In this paper, related studies about alternative lixiviants and methods such as cyanide, thiosulfate, thiourea, thiocyanate, polysulfides, halides, and microbial leaching are summarized. The history, fundamentals, advancements, and challenges of alternative lixiviants are fully concluded to provide a reference for cleaner gold production.
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The data refer to the article "Silver leaching from jarosite-type compounds using cyanide and non-cyanide lixiviants: a kinetic approach" (Islas et al., 2021), in which they were used to determine the leaching kinetics of jarosite-type compounds. The datasets were obtained experimentally from batch experiments.
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It is well-known that the most common and usual process of the leaching with cyanide can be dangerous, needs a great water consumption, and additional costs for remediation of the poisoned and toxic sites. ... Alternative lixiviants to cyanide for leaching gold ores. Dev Miner Process. 2005; 15:501–539. doi: 10.1016/S0167-4528(05)15021-2.
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This paper intends to compare and contrast the non-cyanide gold lixiviants of current interest on the basis of (i) thermodynamics including stability constants of Au (I/III) …
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Numerous non-cyanide leaching lixiviants have been developed, among which thiosulfate is considered the most promising alternative to cyanide due to its non-toxicity, low price, high leaching rate ...
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Cyanide leaching may be used for gold recovery; ... 2020;Syed, 2012;Zhang et al., 2021). The most widely researched non-cyanide lixiviants include thiosulfate, thiourea, halide, thiocyanate, and ...
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Cyanide leaching process can effortlessly cause serious health and environmental problems due to the highly toxic cyanide is used as leaching agent (Jaszczak, 2017, Mohammadi, 2017). Hence, the development and utilization of refractory gold ores in a clean and efficient way have become increasingly urgent in terms of both …
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Section snippets Iodide oxidizing bacteria (IOB) Iodine (I 2), an oxidized form of iodide (I −), is an effective and environmentally-friendly gold leaching agent (Jacobson and Murphy, 1987, Khaing et al., 2019b, Angelidis et al., 1993).It can dissolve gold at a greater rate than cyanide (Angelidis et al., 1993). In an atmosphere of air, both high and …
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In this paper, related studies about alternative lixiviants and methods such as cyanide, thiosulfate, thiourea, thiocyanate, polysulfides, halides, and microbial leaching are summarized. The history, fundamentals, advancements, and challenges of alternative lixiviants are fully concluded to provide a reference for cleaner gold production.
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The operating region of cyanide has the largest and lowest area because the gold-cyanide complex is the most stable among all alternative lixiviants. The leaching of sulfur-containing lixiviants such as thiosulfate, thiourea, thiocyanate, and polysulfides requires a higher potential than cyanide, which leads to their inevitable oxidative ...
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Numerous non-cyanide leaching lixiviants have been developed, among which thiosulfate is considered the most promising alternative to cyanide due to its non-toxicity, low price, high leaching rate ...
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The leaching of Pt and other metals is usually carried out using different lixiviants, such as sulfuric acid, hydrochloric acid, nitric acid, sodium cyanide, chloride or iodide solutions. The oxidizing agents are also added …
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Aqueous lixiviant is a leach liquour capable of dissolving all or part of ore or concentrate. It plays a critical role in the hydrometallurgical process. Although cyanide leaching of gold and silver has demonstrated success in the industry for 100 years, searching for innovative lixiviants to leach gold, copper, and other heavy metals …
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Another big disadvantage of cyanide is its low dissolution rate compared to alternative leaching reagents (lixiviants), which can be more than 10 times faster 2, 7. The cyanide process is the dominant method for gold recovery from ores, but due to different technical and environmental issues the established cyanide process reaches its limit.
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In general, the cyanide gold leaching reaction rate is relatively slow, thus the kinetics of gold leaching with alternative lixiviants has not been a key concern. However, achieving fast gold leaching kinetics and high gold recovery with the alternative lixiviants is important (Hilson and Monhemius, 2006).
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Numerous non-cyanide leaching lixiviants have been developed, among which thiosulfate is considered the most promising alternative to cyanide due to its non-toxicity, low price, high leaching rate and excellent characteristics in dealing with carbonaceous and copper-bearing gold ores. The traditional …
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