— The pretreatment of gold ores before cyanidation is a challenging problem due to the world's annual huge waste of refractory gold minerals. Generally, the leaching of gold by cyanidation without any pre-oxidation causes an extraction lower than 90%. In recent decades, a variety of treatment and pretreatment methods have been used to …
— The application of pressure oxidation (POX) followed by thiosulfate gold leaching is an efficient method used to extract gold from double refractory gold ores containing both sulfide and carbonaceous matter. This process is expected to result in high gold recovery rates, as it liberates gold from sulfides and eliminates the preg-robbing …
— Hypochlorite leaching system is a strong oxidizing solution for metal sulfides, which are naturally associated with gold extraction. This study evaluated the hypochlorite leaching of refractory ...
— The pretreatment of gold ores before cyanidation is a challenging problem due to the world's annual huge waste of refractory gold minerals. Generally, the leaching of gold by cyanidation without ...
— Originally, biotechnology was applied as a bio-oxidation pretreatment for refractory gold ores and concentrates to make it more accessible in cyanidation. As a form of biotechnology that involves high efficiency, ... From an environmental perspective, microbial leaching is undoubtedly the most eco-friendly gold leaching process. Therefore ...
— Pretreatment using microwave-assisted roasting with NaClO 3 as an additive to the oxidizing agent is a new method of processing refractory gold ore. Oxidation was …
Refractory gold ore contains sulfide minerals like pyrite, chalcopyrite and sphalerite that are difficult to be directly leached by cyanidation or by lixiviants such as thiourea and halides. In such cases, it is necessary to perform oxidative pretreatment of the ore to oxidize the sulfide matrix, and gold particles can be exposed to the solution during the leaching process [1]. …
The experimental results showed that under the conditions of liquid solid ratio 3:1, curing temperature 240 °C and the reaction time 1.5 h, the weight loss rate and iron removal …
environmental footprint of direct gold leaching from refractory ores in more aggressive cupric chloride solutions. The modeled direct cupric chloride leaching flowsheet (Figure 1) is based on ... Reference process, chloride leaching and gold recovery are pre-ceded by sulfide breakdown at elevated temperature and pres-sure (190°C, 100 psi ...
— Gold telluride ores are important gold refractory ores due to the presence of sulfides and other gangue materials. The classification and main physical properties of gold telluride ores were described, and possible treatment methods including flotation, leaching, and oxidation were reviewed. The results show that flotation procedures are much …
— Refractory gold ore is usually affected by the associated carbonaceous matter through the preg-robbing effect, which is eliminated by oxidation roasting, followed by leaching, to achieve a satisfactory gold leaching efficiency. Roasting–leaching experiments, pore structure measurements, scanning electron microscopy (SEM), and X …
— Optimization of the pretreatment process of gold refractory ore from Zarshuran gold mine was carried out using Taguchi method-orthogonal array optimization technique (OAOT). ... [21] Aazami M, Lapidus G and Azadeh A 2014 The effect of solution parameters on the thiosulfate leaching of Zarshouran refractory gold ore Int. J. Miner. …
— In this work, a method for the extraction of gold from the cyanide tailings (CT) was investigated. Sulfuric acid was used as a pretreatment leaching solution and calcium hypochlorite was used as a ...
— But the proportion of gold production from refractory ore is just about 30% of the total gold production in the world. As the refractory gold resources have not been utilized well, countries around the world …
— This paper presents the results obtained by processing a gold and silver telluride mineral concentrate from a mine in Colombia. An acid wash, also known as acidification, was carried out, followed by oxidation with nitric acid as a pretreatment. Cyanidations of the pretreatment residues were carried out and the results were …
— The process optimization and mechanism of microwave pyrolysis in a nitrogen atmosphere were studied to improve the gold leaching rate for high-arsenic-refractory gold sulfide resources, mainly containing minerals of elemental sulfur, dense pyrite, and arsenopyrite. The decomposability was evaluated using thermodynamic and …
— The Bacterial Oxidation (BIOX) process for the pre-treatment of refractory ores for gold recovery developed by Genmin, the mining division of Gencor, has been operating successfully at the ...
— As a refractory gold ore, a large proportion of finely disseminated gold is encapsulated in the sulfide matrix of arsenopyrite, resulting in inefficient gold recovery via the conventional leaching ...
— Copper cyanide complexes in cyanide leach solutions deteriorate the recoveries of gold. Herein, five phosphonate-based [P204] − ionic liquids were synthesized, which were pioneered to apply to extraction of copper cyanide complex ions in cyanide leach solutions. In the extraction process, macroscopic layered solids rich in copper …
— In mineral processing, gold ores are commonly classified as (i) free-milling, (ii) refractory gold, and (iii) complex gold ore types, where the free-milling ore type has high gold recovery (>90% ...
— Hypochlorite leaching system is a strong oxidizing solution for metal sulfides, which are naturally associated with gold extraction. This study evaluated the hypochlorite leaching of refractory gold ore by using the response surface method–central composite design (RSM-CCD) as a statistical approach in determining the optimum condition of …
— The current high gold price is increasing the focus on the development of refractory gold ores and concentrates. Outotec can deliver the three main oxidative processes for the treatment of refractory …
— According to a recent article by global consulting firm McKinsey, approximately one-quarter of the gold in geological reserves and resources can be considered refractory, with gold production from refractory ores expected to grow 1.4 % in the next four years, versus 0.3 % for non-refractory ores.
iii and the type of organic solvent. More than 94% of gold could be selectively extracted and recovered after 9 hours which was significantly faster than the current cyanidation process with 35
— The problems during the leaching of gold show the necessity for ore pretreatment to minimize the gold entrapment with refractory minerals and solve the gold low recovery challenge from surrounding …
DOI: 10.1016/j.mineng.2023.108198 Corpus ID: 259698283; Selective alkaline leaching of antimony from Low-grade refractory gold ores and process optimization @article{Zhang2023SelectiveAL, title={Selective alkaline leaching of antimony from Low-grade refractory gold ores and process optimization}, author={Feiyu Zhang and Ya-ru …
The process of crushing or decomposition before gold leaching is called pretreatment of refractory gold. Statistics show that, in the world, about 2/3 gold resource belongs to the …
the effect of impurities in the gold ore or thiourea leaching system on thiourea. The gold in RGOs is usually locked by metal sulfides, such as pyrite, and preg-robbed by carbon …
preparation techniques for the refractory ores. The major developments in the pressure hydrometallurgy of gold ores and concentrates began from the 1980s. The oxidative …
— Effect of nitric acid pre-treatment on the extraction of silver from the ground ore (d 80 : 50 µm) in cyanide leaching (Cyanidation conditions: 1.5 g/L NaCN, pH 10.5, 25 3 C, flow rate of air: 1. ...
— 1. Introduction. At present, more than 35% of China's gold resources (with a total amount of more than 1,000 tons) are difficult to be exploited and smelted, and about 700 tons of gold ores with high arsenic, antimony or sulfur are difficult to be directly cyanide leached (Lei et al., 2016).However, as the gradual depletion of easy-to-treat gold ore …
plying the pretreatment, standard leaching tests with thiosulfate solution were performed to quantify the effects of these three variables on the gold extraction. While only 23 and 29% gold ...
Roasting: This traditional refractory gold pre-treatment option uses superheated air to fluidize the ore, thereby causing the sulphides to oxidize, separate from the gold, and volatilize into sulphur dioxide (SO 2). This method is sometimes referred to as a "Chemical Liberation" process and results in a calcine product that is amenable to ...
— Wu (Wu et al., 2019) and Rusalev (Rusalev et al., 2020) studied the effect of different factors on antimony in the sodium sulfide leaching process for treating high-grade antimony gold ore by electrochemical method. And it is found that the reduced iron powder could effectively decrease gold leaching in Na 2 S leaching solution.
— In this paper, a new process of concentrated sulfuric acid curing pretreatment combined with copper ammonia thiosulfate solution leaching test was …
— A novel pretreatment method for refractory gold ore using ultrasound-activated persulfate was developed to overcome the low extraction efficiency of gold in …
— Arsenious and sulphur-bearing micro-disseminated gold ore is a kind of typical refractory Carlin-Type. The gold in Carlin-Type gold ore grains is distributed finely, existing as invisible or submicroscopic gold, encapsulated in arsenopyrite and pyrite. The technical difficulty of treatment Carlin-Type gold ore lies in how to release the fine gold …
be exposed. Mohammadi et al. investigated ammoniacal thiosulfate leaching of refractory oxide gold ore, and they obtained maximum gold extraction of 55% (Mohammadi et al., 2017). Shen et al. had researched the direct thiosulfate leaching of gold from refractory ore, and they achieved gold recovery of only 70% (Shen et al., 2013).
— 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 …
