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This compares reasonably well with the shape of the elution profiles at this temperature found in the literature (Van der Merwe, 1991). Typical industrial gold elution temperatures range from 110–130°C. As previously been shown in Figure 6, the amount of metal on the carbon affects the rate of adsorption of PGMs onto the carbon.
(Van der Merwe, 1991). During the electrowinning procedure, gold metal is recovered by an electrolytic process, whereby the gold deposits onto the cathode. The laden gold cathodes may contain 7075% gold and 1015% silver, the remaindPf being copper and steel wool.
Whereas Au(CN) 2 − is soluble in water, AuCN and Au require the addition of cyanide to form Au(CN) 2 −. The reversibility of the adsorption of gold onto carbon is a function of the nature of the adsorbed gold and determines the need for cyanide in the elution process, which affects the operating costs of a carboninpulp (CIP) plant.
This compares reasonably well with the shape of the elution profiles at this temperature found in the literature (Van der Merwe, 1991). Typical industrial gold elution temperatures range from 110–130°C. As previously been shown in Figure 6, the amount of metal on the carbon affects the rate of adsorption of PGMs onto the carbon.
treatment on elution of gold Stellenbosch University. agitation showed a decrease of about 10% in Au elution recovery when the agitation .. Deventer and Van Der Merwe (1994), high pre treatment temperature yields The CIP circuit is a well known technology in gold processing. ..
The effect of temperature on the desorption of gold cyanide from activated carbon . By van Deventer and van der Merwe ... 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. ...
Cyanide is added to the feed to the CIL at the trash screen under pan to maximise the gold dissolution. Gravity gold is collected and treated by the Knelson concentrators followed by an intensive cyanidation using the ILR3000BA. The Inline Leach Reactor (ILR) was commissioned in December 2012.
The mechanism of elution of gold cyanide from activated carbon: Authors: van Deventer, J. S. J.; van der Merwe, P . F. ... 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. ... The dynamics of ...
The next process involves electrowinning, which uses electrolysis to separate the cyanide (remaining in solution) and gold (sediment at bottom) ( van Deventer and van der Merwe, 1994). The gold sediment is finally mixed with a little Borax, and smelted, returning in the form of solid gold.
Kinetic Model for the Decomposition of Cyanide during the Elution of Gold from Activated Carbon J. S. J. VAN DEVENTER and P. F. VAN DER MERWE DEPARTMENT OF CHEMICAL ENGINEERING UNIVERSITY OF STELLENBOSCH PRIVATE BAG X5018, STELLENBOSCH, 7600, SOUTH AFRICA ABSTRACT Free cyanide is usually present during the elution of gold cyanide from activated
The elution of gold from activated carbon using deionized water // Journal of the South African Institute of Mining and Metallurgy. — 1997. ... — ISSN X. (англ.) Van Deventer, J. S. J., Van Der Merwe, P. F. The mechanism of elution of gold cyanide from activated carbon // Metallurgical and Materials Transactions B. — 1994.
has been made in understanding the mechanisms and kinetics of gold adsorption onto activated carbon (Van Deventer and Van Der Merwe 1994). Alternative processing options that are less energyintensive and are more able to deal with complex, lower grade ores are in demand, and according to Liddell and Adams (2012), there is
desorption of gold and silver from activated carbon Experiments of gold and silver elution were conducted using several parameters, either fixed or varying parameters. Ethanol volume, temperature and percent solid belonged to varying parameters while loaded carbon, stirring rate, concentrations of NaOH and NaCN served as fixed parameters.
A process is disclosed for the recovery of gold and/or silver values from activated carbon, wherein they are adsorbed as cyanide complexes. The process uses an eluant containing sugar. The process allows the eluant to pass through fresh carbon twice, thereby reducing the volume of the goldloaded eluant. This, in turn, reduces the size of the electrowinning or zinc precipitation circuits.
P. F. Van Der Merwe''s 7 research works with 107 citations and 2,007 reads, including: Kinetic Model for the Decomposition of Cyanide during the Elution of Gold from Activated Carbon
van der Merwe, 1994). ... can be incorporated into a dynamic model describing a continuous shift in the adsorption/desorption equilibrium as elution elution of gold cyanide is ...
Van der Merwe (1991) and Stange (1991) showed that the elution of gold is dependent on the removal of the sodium or potassium introduced in the pretreatment step. The extent of cyanide decomposition determines the passivation of the carbon surface and the decrease in the equilibrium isotherm for gold loading (Van der Merwe, 1991).
Discussion on the kinetics of the elution of gold from activated carbon ... The contributions of H. Jacobs and Van der Merwe who confirmed the findings as part of a final year student project ... Jc = flux of gold cyanide across the outer carbon layer
Fundamentals of the elution of gold cyanide from activated carbon . By Pieter F.(Pieter Francois) Van der Merwe. Abstract. Dissertation (Ph. D. (Ing.)) University of Stellenbosch, text to be digitised and attached to bibliographic record
point, and experiments suggest the possibility of an optimum cyanide concentration, beyond which elution efficiency starts decreasing. Introduction The carboninpulp or carboninleach (CIP and CIL) processes have been the main commercial processes on almost every gold plant built since 1980 (Fleming, 1992; Van Deventer, 1984).
Abstract 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 industry.
Mar 01, 2003· Ultrasonic elution of gold from activated carbon Ultrasonic elution of gold from activated carbon Feng, D; Tan, H; van Deventer, 00:00:00 The feasibility of using ultrasound to enhance the elution of gold from activated carbon was investigated. A laboratoryscale elution column immersed in an ultrasonic bath was used to investigate three eluant systems.
Van Deventer and Van der Merwe (1994) developed a generalised model to simulate the more complex AARL process. Equilibrium conditions may be assumed in an elution column when adsorption is weak, while diffusional phenomena become rate controlling when desorption is weak towards the end of a elution cycle. o 5 10 15 BEDVOLUMES
from active carbon surface venter (van De and van der Merwe, 1994). The organic solvent, either ethanol or acetonitrile, is able to increase CNand Au(CN) 2activities. As a result, the released ... size of activated carbons with gold cyanide for subsequent elution experiments as setup in Figure 1. Coarse granular activated
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