scholarly journals Intensification Behavior of Mercury Ions on Gold Cyanide Leaching

Metals ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 80 ◽  
Author(s):  
Qiang Zhong ◽  
Yongbin Yang ◽  
Lijuan Chen ◽  
Qian Li ◽  
Bin Xu ◽  
...  
Keyword(s):  
Mercury Ions ◽  
Gold Cyanide ◽  
Cyanide Leaching

scholarly journals CIL Gold Loss Characterization within Oxidized Leach Tails: Creating a Synergistic Approach between Mineralogical Characterization, Diagnostic Leach Tests, and Preg-Robbing Tests

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 557 ◽  
Author(s):  
Mohamed Edahbi ◽  
Raphaël Mermillod-Blondin ◽  
Benoît Plante ◽  
Mostafa Benzaazoua
Keyword(s):  
Mineralogical Composition ◽  
Carbonaceous Matter ◽  
Gold Cyanide ◽  
Cyanide Leaching ◽  
Native Form ◽  
Mineralogical Characterization ◽  
Sulphide Minerals ◽  
Refractory Gold ◽  
Synergistic Approach ◽  
Final Residue

A double refractory gold ore contains gold particles locked in sulphides, solid-solution in arsenopyrite, and preg-robbing material such as carbonaceous matter, and so on. The diagnostic leach test (DLT) and preg-robbing (PR) approaches are widely used to investigate the occurrence and the distribution of refractory gold. DLT serves to qualitatively evaluate the gold occurrences within the ore. Preg-robbing, or the ore’s capacity to fix dissolved gold, is evaluated to determine physical surface interactions (preg-borrowing) and chemical interactions (preg-robbing). The objective of this project is to characterize the refractory gold in Agnico Eagle Mine’s Kittilä ore using the DLT and PRT approaches coupled with mineralogical analyses to confirm testing. The studied material was sampled from the metallurgical circuit following carbon in leach (CIL) treatment at the outlet of the autoclave in order to investigate the effect of the autoclave treatment on the occurrence and distribution of gold. Different reagents were used in the DLT procedure: sodium carbonate (Na2CO3), sodium hydroxide (NaOH), hydrochloric acid (HCl), and nitric acid (HNO3). The final residue was roasted at a temperature of around 900 °C. These reagents were selected based on the mineralogical composition of the studied samples. After each leaching test/roasting, cyanide leaching with activated carbon was required to recover gold cyanide. The results show that gold is present in two forms (native and/or refractory): to a small extent in its native form and in its refractory form as association with sulfide minerals (i.e., arsenopyrite and pyrite) and autoclave secondary minerals that have been produced during the oxidation and neutralization processes such as iron oxides, iron sulfates, and calcium sulfate (i.e., hematite and jarosite), along with carbonaceous matter. The results of DLT indicate that 25–35% of the gold in the tails is nonrecoverable, as it is locked in silicates, and 20–40% is autoclave products. A regrind can help to mitigate the gold losses by liberating the Au-bearing sulphide minerals encapsulated within silicates.

scholarly journals Study on Intensification Behavior of Bismuth Ions on Gold Cyanide Leaching

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 362 ◽  
Author(s):  
Yongbin Yang ◽  
Meixiang Lai ◽  
Qiang Zhong ◽  
Qian Li ◽  
Bin Xu ◽  
...  
Keyword(s):  
Anodic Dissolution ◽  
Gold Surface ◽  
Corrosion Current ◽  
Electrochemical Analysis ◽  
Anode Current Density ◽  
Gold Cyanide ◽  
Cyanide Leaching ◽  
Structure Information ◽  
Passivation Film ◽  
Gold Plate

Gold cyanide leaching is inefficient with conventional cyanidation. Bismuth ions can improve the efficiency of gold cyanidation by intensifying gold dissolution. The electrochemical behavior, structure information, and surface product of gold anodic dissolution were studied during the intensification of bismuth ions on gold cyanide leaching. The electrochemical analysis showed that the bismuth ions can not only improve anode current density, but also make gold dissolve at a lower potential, increase the corrosion current and intensify gold anodic dissolution. The microstructure analysis showed that bismuth ions intensified the cyanide corrosion of the gold surface, causing a large number of loose honeycombs, gullies, pits, and large holes on the gold surface. The XPS, FT-IR, and Raman analysis showed that there is weak information of C≡N in the spectrum of Bi intensification contrasting to that of conventional cyanidation. Cyanide compounds may be the insoluble AuCNads, which does not deposit on the surface of gold plate after Bi intensification cyanidation. The insoluble intermediate AuCNads is likely to react promptly with CN- to form soluble Au(CN ) 2 − , making less insoluble AuCNads deposits on the gold surface. Therefore, bismuth ions can promote the dissolution of insoluble AuCNads, prevents its passivation film to cover around the gold plate, keeps cyanide good contact with gold, and finally accelerates the cyanide dissolution of gold.

Co-intensification of cyanide leaching gold by mercury ions and oxidant

2010 ◽  
Vol 20 (8) ◽  
pp. 1521-1526 ◽  
Author(s):  
Qian LI ◽  
Tao JIANG ◽  
Yong-bin YANG ◽  
Guang-hui LI ◽  
Yu-feng GUO ◽  
...  
Keyword(s):  
Mercury Ions ◽  
Cyanide Leaching

Features of Gold Cyanide Leaching in a Grinding Cycle

Metallurgist ◽  
2013 ◽  
Vol 57 (7-8) ◽  
pp. 654-658
Author(s):  
V. V. Elshin ◽  
A. A Kolodin ◽  
A. E. Ovsyukov ◽  
A. S. Mal’chikhin
Keyword(s):  
Gold Cyanide ◽  
Cyanide Leaching

scholarly journals Effect of hydrogen peroxide and lead(II) nitrate on gold cyanide leaching of Malaysian mesothermal deposit gold ore

2020 ◽  
Vol 56 (5) ◽  
pp. 905-918
Author(s):  
Norlia Baharun ◽  
Ong Pek Ling ◽  
Mohammad Rezaei Ardani ◽  
Kamar Shah Ariffin ◽  
Ali Yaraghi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Gold Cyanide ◽  
Cyanide Leaching ◽  
Gold Ore

A geometallurgical characterization study of the Crystalkop Reef at the Great Noligwa Mine, Klerksdorp Goldfield, South Africa

2017 ◽  
Vol 120 (3) ◽  
pp. 303-322
Author(s):  
D. Pienaar ◽  
B.M. Guy ◽  
C. Pienaar ◽  
K.S. Viljoen
Keyword(s):  
South Africa ◽  
Treatment Plant ◽  
Processing Parameters ◽  
Processing Plant ◽  
Small Contribution ◽  
Gold Cyanide ◽  
Three Samples ◽  
Characterization Study ◽  
Different Sources

Abstract Mineralogical and textural variability of ores from different sources commonly leads to processing inefficiencies, particularly when a processing plant is designed to treat ore from a single source (i.e. ore of a relatively uniform composition). The bulk of the Witwatersrand ore in the Klerksdorp goldfield, processed at the AngloGold Ashanti Great Noligwa treatment plant, is derived from the Vaal Reef (>90%), with a comparatively small contribution obtained from the Crystalkop Reef (or C-Reef). Despite the uneven contribution, it is of critical importance to ensure that the processing parameters are optimized for the treatment of both the Vaal and C-Reefs. This paper serves to document the results of a geometallurgical study of the C-Reef at the Great Noligwa gold mine in the Klerksdorp goldfield of South Africa, with the primary aim of assessing the suitability of the processing parameters that are in use at the Great Noligwa plant. The paper also draws comparisons between the C-Reef and the Vaal Reef A-facies (Vaal Reef) and attempts to explain minor differences in the recovery of gold and uranium from these two sources. Three samples of the C-Reef were collected in-situ from the underground operations at Great Noligwa mine for mineralogical analyses and metallurgical tests. Laboratory-scale leach tests for gold (cyanide) and uranium (sulphuric acid) were carried out using dissolution conditions similar to that in use at the Great Noligwa plant, followed by further diagnostic leaching in the case of gold. The gold in the ore was found to be readily leachable with recoveries ranging from 95% to 97% (as opposed to 89% to 93% for the Vaal Reef). Additional recoveries were achieved in the presence of excess cyanide (96% to 98%). The recovery of uranium varied between 72% and 76% (as opposed to 30% to 64% for the Vaal Reef), which is substantially higher than predicted, given the amount of brannerite in the ore, which is generally regarded as refractory. Thus, the higher uranium recoveries from the C-Reef imply that a proportion of the uranium was recovered by the partial dissolution of brannerite. As the Vaal Reef contain high amounts of chlorite (3% to 8%), which is an important acid consumer, it is considered likely that this could have reduced the effectiveness of the H2SO4 leach in the case of the ore of the Vaal Reef. Since the gold and uranium recoveries from the C-Reef were higher than the recoveries from the Vaal Reef, the results demonstrate that the processing parameters used for treatment of the Vaal Reef are equally suited to the treatment of the C-Reef. Moreover, small processing modifications, such as increased milling and leach retention times, may well increase the recovery of gold (particularly when e.g. coarse gold, or unexposed gold, is present).

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