the mechanism of elution of gold cyanide from activated

the mechanism of elution of gold cyanide from activated

The mechanism of elution of gold cyanide from activated ...

Numerous articles have appeared on the mechanism of the adsorption of gold cyanide onto activated carbon. In contrast, little information is available on the mechanism of elution of the adsorbed gold. It is the objective of this article to formulate such a mechanism on the basis of batch and column elution tests without analyzing adsorbed species on the carbon directly. The presence of ...

The mechanism of elution of gold cyanide from activated ...

1994-12-1 · Numerous articles have appeared on the mechanism of the adsorption of gold cyanide onto activated carbon. In contrast, little information is available on the mechanism of elution of the adsorbed gold. It is the objective of this article to formulate such a mechanism on the basis of batch and column elution tests without analyzing adsorbed species on the carbon directly.

Fundamentals of the elution of gold cyanide from

ENGLISH ABSTRACT: Most research work on activated carbon systems has been concerned only with the adsorption process. Nevertheless, controversy still exists on the mechanism by which metal cyanide complexes such as Au(CN)2 are adsorbed onto activated carbon, and whether these complexes are decomposed to irreversibly adsorbed species, such as AuCN and Au( 0l.

Fundamentals of the elution of gold cyanide from

As the concentrations of cyanide and the spectator cations, as we 11 as their reactions, were found to affect the gold cyanide equilibrium, these factors had to be accounted for in modelling the gold elution process. The system was simplified by using only one cation, namely potassium. Models were then developed to simulate the changes in ...

The elution of gold from activated carbon using deionized ...

SYNOPSIS The pretreatment of gold-loaded activated carbon with a relatively strong sodium cyanide solution prior to elution with deionized water at 90 to 125°

[PDF] The mechanism of the adsorption of gold cyanide on ...

Corpus ID: 52993744. The mechanism of the adsorption of gold cyanide on activated carbon @article{McDougall1980TheMO, title={The mechanism of the adsorption of gold cyanide on activated carbon}, author={David J. McDougall and Robert D. Hancock and Michael J. Nicol and Owusu Wellington and Richard George Copperthwaite}, journal={Journal of The South African Institute of Mining and

Factors affecting the elution of gold cyanide from ...

The elution of gold cyanide is suppressed by the presence of cations (M n+) through the formation of M n+ (Au (CN) 2−) on the carbon. The horizontal position of the gold peak in an AARL elution profile was found to be a function of the elution of the cations from the carbon bed.

Factors affecting the elution of Pt, Pd and Au cyanide ...

2015-9-1 · The elution system’s temperature can be increased through a hot acid wash without eluting any gold or silver from the activated carbon which will increase the efficiency of the subsequent elution. Severe calcium passivation can have a negative impact on the subsequent elution of gold which will be eliminated through the acid washing step.

The effect of temperature on the desorption of gold ...

1993-6-28 · Activated carbon is used worldwide for the extraction of gold cyanide from leached pulps. The elution of gold cyanide is usually conducted by soaking the loaded carbon in an alkaline solution of cyanide in a column, followed by a rinse with water at temperatures higher than 100° C.

Studies on the mechanism of gold adsorption and elution

This thesis is a fundamental study of the adsorption and desorption of gold cyanide from activated carbon. Emphasis was placed on defining the adsorption mechanism of Au(CN)2 on activated carbon and in understanding the chemistry of the elution procedure which uses organic solvents to promote the desorption of Au(CN)2 • The results improve our understanding of the Carbon-in-Pulp process, and ...

Fundamentals of the elution of gold cyanide from

As the concentrations of cyanide and the spectator cations, as we 11 as their reactions, were found to affect the gold cyanide equilibrium, these factors had to be accounted for in modelling the gold elution process. The system was simplified by using only one cation, namely potassium. Models were then developed to simulate the changes in ...

[PDF] The mechanism of the adsorption of gold cyanide on ...

Corpus ID: 52993744. The mechanism of the adsorption of gold cyanide on activated carbon @article{McDougall1980TheMO, title={The mechanism of the adsorption of gold cyanide on activated carbon}, author={David J. McDougall and Robert D. Hancock and Michael J. Nicol and Owusu Wellington and Richard George Copperthwaite}, journal={Journal of The South African Institute of Mining and

Factors affecting the elution of gold cyanide from ...

The elution of gold cyanide is suppressed by the presence of cations (Mn+) through the formation of Mn+ (Au (CN)2-) on the carbon. The horizontal position of the gold peak in an AARL elution profile was found to be a function of the elution of the cations from the carbon bed. High temperatures and intense cyanide pre-treatment, i.e. conditions ...

The elution of gold from activated carbon at room ...

1994-8-1 · The elution of gold from activated carbon at room temperatures using sulphide solutions . M.D. Adams; ... which confirms that the elution mechanism in the case of sulphide is different from that when cyanide or hydroxide is used as the eluant. It is proposed that the elution of gold by sulphide solutions proceeds by means of an initial step ...

Process for eluting precious metals from activated carbon ...

1999-8-13 · The importance of these two reagents in the elution process is illustrated in numerous studies on the mechanism of adsorption and elution of gold cyanide from activated carbon. Thus, Davidson established that the addition of "spectator cations" could enhance appreciably the gold adsorption following the sequence, Ca 2 + >Mg 2 + >H + >Li + >Na ...

(PDF) Gold complexes and activated carbon - A literature ...

A CBCS pilot test to recover gold from 200 dm3 of the cyanide solution containing (mg dm−3) 2.6 Au, 0.42 Ag, and 490 Cu was carried out. The total amount of noble metals (Au + Ag) adsorbed was ...

Ultrasonic elution of gold from activated carbon ...

2003-3-1 · The Anglo elution procedure ( Davidson and Duncanson, 1977; Davidson and Veronese, 1979) is an alternative approach, which elutes gold in 8–12 h using deionised water at 100–120 °C. In this procedure, the carbon is pre-soaked with 5% w/v NaCN/1% w/v NaOH solution. This process is sensitive to the quality of water used.

Chapter 8

2016-3-21 · precipltation of gold and silver from cyanide solutions. This occurred at about the same time as the introduction of the cyanidation process, the history of which is recapped in Chapter 1. The initial cementation process involved introduction of a gold-bearing cyanide solution onto a bed of zinc shavings.

The mechanism of adsorption of aurocyanide onto

A dual mechanism for the adsorption of Au(CN) 2 − and Ag(CN) 2 − onto activated carbon is therefore proposed, in which cyanide complexes adsorb on carbon by anion exchange with OH− followed ...

Studies on the mechanism of gold adsorption and elution

This thesis is a fundamental study of the adsorption and desorption of gold cyanide from activated carbon. Emphasis was placed on defining the adsorption mechanism of Au(CN)2 on activated carbon and in understanding the chemistry of the elution procedure which uses organic solvents to promote the desorption of Au(CN)2 • The results improve our understanding of the Carbon-in-Pulp process, and ...

Factors affecting the elution of gold cyanide from ...

The elution of gold cyanide is suppressed by the presence of cations (Mn+) through the formation of Mn+ (Au (CN)2-) on the carbon. The horizontal position of the gold peak in an AARL elution profile was found to be a function of the elution of the cations from the carbon bed. High temperatures and intense cyanide pre-treatment, i.e. conditions ...

THE EFFECT OF ACTIVATED CARBON PARTICLE SIZE ON

2015-7-7 · The effect of particle size on gold adsorption and elution from activated carbon has been studied in alkaline solution, in order to understand the nature of gold losses on fine activated carbons, to improve the rate of gold recovery, and to develop an innovative way of treating preg-robbing gold ores. Four stripping techniques (atmospheric Zadra,

The elution of gold from activated carbon at room ...

1994-8-1 · The elution of gold from activated carbon at room temperatures using sulphide solutions . M.D. Adams; ... which confirms that the elution mechanism in the case of sulphide is different from that when cyanide or hydroxide is used as the eluant. It is proposed that the elution of gold by sulphide solutions proceeds by means of an initial step ...

Elution behaviour of metals from carbon

2009-10-15 · Many gold plants process ores containing traces of mercury, but the deportment of mercury through the entire plant under different operating conditions is poorly understood. It is known that generally mercury follows gold through the cyanide circuit (Zárate, 1985) and loads onto the activated carbon, but only partially elutes with the gold ...

Kinetic Model for the Decomposition of Cyanide during

2006-9-23 · Free cyanide is usually present during the elution of gold cyanide from activated carbon. The decomposition of cyanide is important not only in the extraction of gold but also for environmental reasons. Previous studies have indicated that competitive adsorption of cyanide with aurocyanide plays a minor role at the elevated temperatures used in ...

Selective elution of gold, silver and mercury cyanide from ...

2010-11-1 · A high-pressure laboratory elution rig was commissioned to simulate industrial Zadra and AARL elution conditions for the stripping of gold, silver and mercury from loaded activated carbon. It was found that cyanide was essential for the efficient elution of both mercury and silver, while gold was found to elute most effectively in hot, low-ionic strength solutions. Therefore, the standard AARL ...

The nature of uptake and elution of gold from iodide ...

The mechanism of gold uptake from iodide solutions by carbon has been investigated. A variety of samples of activated carbon were used. Adsorption isotherms for gold and triiodide were established and successive loading tests of gold and triiodide on carbon were also accomplished. ... Thermal pressure elution is very effective for gold cyanide ...

The mechanism of adsorption of aurocyanide onto

A dual mechanism for the adsorption of Au(CN) 2 − and Ag(CN) 2 − onto activated carbon is therefore proposed, in which cyanide complexes adsorb on carbon by anion exchange with OH− followed ...

Chapter 8

2016-3-21 · precipltation of gold and silver from cyanide solutions. This occurred at about the same time as the introduction of the cyanidation process, the history of which is recapped in Chapter 1. The initial cementation process involved introduction of a gold-bearing cyanide solution onto a bed of zinc shavings.