Copper – ethylenediamine – thiosulfate leaching is described as an alternative green way of gold extraction. Under optimal conditions, a gold extraction efficiency of 80.3% is …
Gold ores that are not amenable to direct leaching by cyanide or any other leachant are known as refractory ores. The primary reason for this poor response is mineralogical (Robinson, 1983), with the gold being finely disseminated in the sulphide minerals such as pyrite, pyrrhotite, chalcopyrite, arsenopyrite, etc.In a broad classification of the gold ores (La Brooy et …
In this study, we conducted experiments to characterize the effects on gold extraction of ores using a range of sodium cyanide concentrations (1–8 g/L), temperatures (40–75 °C), and oxygen ...
Extraction of gold and silver from refractory complex sulphide ores requires some pre-treatment, such as roasting, pressure oxidation and bio-leaching, followed by neutralization and standard cyanidation or alternative thiourea leaching. A novel method, presented in this paper, demonstrates that the refractory gold and silver can be extracted ...
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 …
of non-refractory and refractory gold. Gold in non-refractory sulfide ores can be recovered by whole-ore cyanidation, or some combination of flotation and cyanidation. Acceptable extraction of refractory gold can only be achieved by employing a pre-oxidation process prior to cyanide leaching. Antimony, bismuth sulfide and telluride
When the gold or silver are locked up in the mineral matrix, they remain unrecovered and the ore is classified as refractory to cyanidation. Ozonization in acidic media of an arsenopyritic-pyritic highly refractory gold concentrate (110 g Au/t) as a treatment prior to cyanidation was evaluated.
A good amount of fire methods and wet processes have shown potential for gold extraction from refractory resources (Chakraborti and Lynch, 1983; Linge, 1995; Espiell et al., 1986). While, several reasons have arisen for the preference of a wet way, including growing energy costs and carbon relieving pressure. As it is well known, a wet method ...
Cyanide leaching, as a typical traditional method, hardly achieves the cleaner production of gold due to high consumption of auxiliary materials, inefficient production and heavy environmental pollution.In this work, stepwise thiourea leaching was used to extract gold and silver from refractory gold concentrate calcine. In the first stage, gold and silver …
The influences of various factors (ammonium persulfate concentration, potassium iodide concentration, pH, and leaching time) on the gold extraction rate were studied, and the leaching conditions for extracting gold from a typical refractory gold ore using the S 2 O 8 2− – I − – H 2 O system were optimized. In addition, the recovery of ...
Under neutral conditions, the gold extraction rate from refractory ore reaches 80%. The S 2 O 82− − I − − H 2 O system provides a green and economical gold leaching method. …
Previous researchers reported that gold extraction was relatively low when leaching was carried out directly on refractory gold without pretreatment (Celep et al., 2019; Qin, Guo, Tian, Yu, et al ...
It has been suggested that refractory gold reserves, which require more sophisticated treatment methods in order to achieve oxide-ore recovery rates, correspond to 24% of current gold reserves and 22% of gold resources worldwide. ... and most is located in regions with a long history of gold exploration and mining, as well as a lower investment ...
The factors affecting gold extraction from refractory ores in general and the available processing options f o r t h e i r treatment were recently discussed by Demopoulos (1987). The c l a s s i c a l commercial practice applied f o r the treatment of this type of r e f r a c t o r y gold ores usually involves an oxidation roast ( s i n g l e ...
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 gold extraction from …
To realize the efficient comprehensive utilization of refractory gold ore resources and environmental and economic gold extraction methods, this study investigated the optimal chlorine source for the sustained recovery of gold and vanadium from carbonaceous refractory gold ore by chlorination heat treatment. During the chlorination roasting process, the results …
1. Introduction. The efficiency of gold extraction from sulphidic refractory ores (e.g., arsenopyrite (FeAsS) and pyrite (FeS 2)) by direct cyanidation is usually very low (Badri and Zamankhan, 2013, Faraz et al., 2014), since fine gold particles in these ores are mostly locked up in the bulk and therefore inaccessible to leaching agents and dissolved oxygen (Badri and …
Additionally, conventional thiourea leaching cannot extract gold efficiently from refractory gold concentrate calcine samples, due to the complicated chemical composition of gold minerals (Eymery and Ylli, 2000). Part of gold is still encapsulated in the iron oxides and quartz minerals even if the gold concentrate with high-sulfur and high ...
ABSTRACT. This review presents an updated data on various technologies for the processing of refractory gold-bearing sulfide concentrates. It primarily focuses on the hydrometallurgical treatment for sulfide mineral oxidation and gold extraction, including the use of bacteria, pressure oxidation, ultrafine grinding, and the Albion Process TM.The main operating plants …
Pyrometallurgical processing is shown to be promising for treating ores obtained from refractory and double-refractory gold deposits. Problems related to the effective …
Typically, gold is encapsulated or finely disseminated in refractory gold ores and the direct cyanidation is not effective for gold extraction from these ores, even after the ore is ground to exceeding small particles (Nazari, 2017, Corrans and Angove, 1991).Especially for sulfide refractory gold ores, in order to recover gold, many oxidation pretreatment …
Most gold deposits occur associated with sulphides like pyrite and arsenopyrite; thus, precious metal dissolution is possible by oxidizing auriferous sulfide concentrate using …
Moreover, the use of IOB could be explored for extracting gold from refractory gold ores to determine whether a prior oxidation step is required before iodine-based gold bioleaching. Acknowledgments. The authors would like to thank King Mongkut's University of technology Thonburi (KMUTT) through the Petchara Pra Jom Kloa PhD scholarship ...
Re-fractory ores, however, require fine grinding and a further pre-treatment step, such as roasting and pressure oxidation, to render the gold ores amenable to extraction. Usually, …
It can be seen from Table 1 that the main valuable element for recovery in the tailings is gold, which has the gold grade of 10.00 g/t. Table 2 showed that the gold mainly exists in the occluded gold, in which 18.39 %, 22.18 %, and 59.43 % of gold are encased in the hematite, sulfide mineral, and silicate gangue mineral, respectively. The occluded gold is …
Most gold deposits occur associated with sulphides like pyrite and arsenopyrite; thus, precious metal dissolution is possible by oxidizing auriferous sulfide concentrate using simultaneous pressure oxidation and cyanidation. The effectiveness of this ... Gold Extraction from a Refractory Sulfide Concentrate by Simultaneous Pressure Leaching ...
Problem with gold recovery from sulphide ore: How may a mill get the maximum recovery of gold from a sulphide ore, at the least capital cost and at the same time obtain the highest net return.This latter point is most important. In many cases a gold mill using an all-cyanide flowsheet with fine grinding of all the ore will report very low gold content in the …
The most promising results were obtained utilizing solution with sodium sulfite and sodium sulfate concentration of 25 g/L and leaching time – 1 hour. Under these conditions, the extraction of gold was 67%. The use of sodium sulphate and sodium sulfite allows to extract gold and partially silver from refractory sulfide ores.
These studies mainly consider the effect of MW-assisted roasting conditions on gold extraction and impurity removal from refractory gold ores. Citric acid (CA) has been widely used in water treatment, mineral flotation, and cleaning due to its advantages of nontoxicity, low cost, and chelation effect for many metal ions, e.g., iron ( Silva et ...
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 extraction of gold from refractory gold ores (RGOs) without side reactions is an extremely promising endeavor. However, most RGOs contain large amounts of sulfide, such as pyrite. Thus ...
For a refractory ore, pretreatment is required in order to expose the gold surface to the leach solution. An acidic hypochlorite solution can be added to the autoclave for pressure oxidation and extraction of the gold at the same time. It required 50 % sodium hypochlorite or 120 kg/t available chlorine to extract 97 % of the gold from the ore.
MA Long. Extraction of Gold from a Refractory Gold Concentrate Containing Chalcopyrite by Thiourea Leaching in Jilin[J]. Multipurpose Utilization of Mineral Resources, 2011, (4): 18-21. doi: 10.3969/j.issn.1000-6532.2011.04.005
The presence of arsenic in the ore is extremely harmful to the cyanidation gold extraction process, and sometimes even makes the cyanidation process impossible. The effective utilization of such refactory ores has become one of the important topics in the gold mining industry. 02 Gold ore recovery process
The gold extraction experienced a decrease of approximately 7% as the pulp pH increased from 1.00 to 3.50. Hence, the most suitable pH for the system is determined to be 1.00. ... Extraction of gold from refractory gold ore using bromate and ferric chloride solution. Miner. Eng., 136 (2019), pp. 89-98. View PDF View article View in Scopus ...
Table 4 Summary of selected US patents related to gold extraction/recovery US Patent No. Title 4,578,163 Gold recovery process Date Summary of Process 25/3/86 Treatment of refractory ores Pressure oxidation, cyanidation and CIP recovery Flowsheet provided in Appendix A 4,597,791 Gold recovery processes 1/7/86 4,681,628 Gold recovery processes ...
The 21 m 3 demonstration scale was used to extract the required process design correlations required for the design of the ... For the processing of free-milling ores to refractory gold ores ...
Colloquium on Refractory Gold Ore Treatment, Western Australian School of Mines, Kalgoorlie WA, 3 (1988) Linge, H.G. New technology tbr refractory gold ores. huernational Conference on Extractive Metallurgy of Gold and Base Metals Kalgoorlie, WA 26-28 October, Aus.I.M.M, Melbourne, 339 (1992).
