10.5 by addition of 5.0g of lime. The retention time for leaching experiments was varied between 24 to 96 hours. The mineralogical composition and gold recovery were determined using Atomic Absorption Spectrometer AAS and X ray fluorescent XRF. No attempt was made to grind
Jul 07, 2016 The effect of ore particle size on gold recovery is usually studied using mono-size particles and experimental results indicate that gold recovery increases with the increasing neness of the grind 2,3. Other studies report similar results from leaching bulk coarse ore samples without referring to the individual ore size fractions 4.
The carbon-in-leach CIL process is one the most efficient methods of gold recovery from gold bearing ores. The efficiency of the leaching process greatly depends on the flow structure created by mechanical agitation in some cases air agitation in the leaching tanks. Residence time distribution RTD measurement was conducted in the CIL section of a gold processing plant in order to ...
144 J. Mex. Chem. Soc. 2012, 562 Mar a Isabel Reyes et al. Total Recovery of Gold Contained in Computer Printed Circuit Boards. Leaching Kinetics of Cu, Zn and Ni Mar a Isabel Reyes,1 Isauro Rivera,1 Francisco Pati o,1 Mizraim U. Flores,1 and Mart n Reyes1 1 rea Acad mica de Ciencias de la Tierra y Materiales, UAEH, Ciudad Universitaria Carretera Pachuca-Tulancingo Km. 4.5,
A population balance model can incorporate each of these key factors. The power of the model not only helps to predict gravity gold recovery but can also assist in trouble shooting existing circuits. The GRG Test Ore Characterization The gravity-recoverable-gold content of an ore, as obtained via a GRG test, provides a quantitative theoretical limit of gold that can be recovered using a BCC.
In this study, the effects of pH, time and temperature in regeneration of cyanide in the leaching waste solution of gold production from disseminated gold ore by cyanidation process were investigated and the optimum conditions, consumptions and cyanide recovery values were determined. The sample of waste solution containing 156 mgl free CN- and 358 mgl total CN-, that was obtained from ...
Leaching reagents in the form of cyanide and an oxidant such as air or oxygen are added after thickening. Leaching takes place in a series of agitated leach reactors or pachucas. Before leaching the pH of the pulp is normally adjusted to a value of around 9.511 to ensure minimum loss of cyanide as hydrogen cyanide.
from the dissociation of the complex is used to leach gold from the ore. The stepwise dissociation of cyanide from copper-cyanide complexes can also be used to leach gold from a variety of oxide and sulphide ores. The copper cyanides fourth ligand readily dissociates at low cyanide concentrations for use in gold leaching.
Oct 13, 2011 When the attack time is over, a shiny, solid product has been obtained it was characterized by SEMEDS and AAS, confirming that it is metallic gold, with a purity of 100 and 99.9 according to the respective technique. Key words Gold, printed circuit boards, kinetics, leaching, recovery. Resumen
Here, the recovery of accompanying The leaching kinetics of gold and silver were best fitted Me 100 metals was 87 for Cu, 55 for Fe and 28 for Zn. by the kinetic equation ln 1 x k X t L 1 where x is recovery of goldsilver into the leach solution, kX 80 Au is the rate constant s-1 and tL is the leaching time s.
received attention and new rate equations expressing the gold leaching are still developed. The effect of leaching parameters on gold cyanidation is studied in this work in order to optimize the leaching process. A gold leaching model, based on the well-known shrinking-core model, is presented in this work. It is proposed that
The optimum recovery of gold with NaOCl is 98.86 Au at leaching temperature of 40 C, solvent concentration 5 M, NaOCl 5 mL and 20 solid after 120 minutes leaching time. Silver loss under this condition is 23. Leaching the gold by H2O2 provided the highest gold extraction of 99.99 Au at 7M HCl concentration, temperature 60 C, H2O2 0.5 ...
The aim of this study was to investigate the availability and fate of cyanide in gold mill solid tailings. For this purpose, aged 6-9 years and recently discharged 3 months tailings were sampled at various depths from two gold mining sites in Quebec Canada. A physicochemical characterization o
cyaniding process, used for the recovery of gold, have promoted the study in this topic by searching for alternate leaching reagents. From the results found, the chloride, thiourea, and thiosulfate could serve as an alternative Gurung et al., 2013. Senanayake 2005 carried out a critical study of the gold leaching
The traditional gold leaching method is cyanidation, which carries serious security and environmental problems. More and more attention is paid to the research on non-cyanide process. A high-arsenic-and-sulphur refractory gold concentrate in Sichuan was taken as the object of study. After the roasting-oxidation pretreatment of the sample, potassium ferricyanide was adopted to carry on the ...
From a literature review leaching of gold ores, mostly, it was found that there are two research lines. Some authors worked with lower concentrations of thiosulfate and ammonium for a leaching time of 4 hours, whereas others worked with higher concentrations of thiosulfate and ammonium and a leaching time of 24 hours OMalley, 2002 OMalley, G. P. Recovery of Gold from Thiosulfate ...
Make sure the leaching slurry concentration is not less than 0.015 to efficiently leach the gold ore. At the same time, lime is added to maintain a higher pH 10-11. ... the concentration of CNLITE ECO gold leaching agent and oxygen are closely related to the gold recovery rate. The metal zinc is added to the pregnant solution after ...
Jul 22, 2017 The ideal leaching time was defined as that needed to extract enough arsenic such that a high extraction of gold would result from the cyanidation of the oxidative leach residue. The overall results indicate that the best leaching conditions for extraction of more than 90 pct arsenic were 2M NaOH, 100 C, 40 psig, 100 gL ore, and 4 to 7 h.
Sep 16, 2019 methodology aiming to explore, for the first time, this aspect using a synergistic approach between mineralogical characterization, diagnostic leach tests, and preg-robbing tests. Figure 1. Gold recovery and difference normalized as a function of Au grade A and B and C tot content C and D, respectively.
indication of gold recovery could be obtained by conducting fire assays on head and tails samples. Gold Recovery Gold recoveries from cyanide leaching varied significantly across the samples from this gold ore site and ranged from 9100. This indicates a variability in the refractory nature of gold
Effect of leaching time The effect of leaching time on the recovery of metals Zn, Fe and Cu were studied at constant sulfuric acid concentration 2mol.L-1, particle size 63 m for solid-to-liquid ratio 110 and at a temperature of leaching solution of 85 C. Figure 4 Effect of leaching time on leaching. 0.5 1.0 1.5 2.0 20 40 60 80 100
SGS metallurgists developed and continue to improve on these cost-effective, time-tested and proven processes. In each, activated carbon is used to extract gold from the cyanide leach solution. Such a carbon recovery system offers high recovery rates and lower capital and operating costs. These carbon recovery techniques include Carbon-in-pulp.
leaching tests were also performed to shed light on the refractory characteristics of ore. The leaching tests show that the extraction of gold and silver is consistently low, i.e. 47 and 19.2, respectively, over a leaching period of 24 h. Even fine grinding e.g. 38 m
Jun 01, 2009 Diagnostic leaching tests were also performed to shed light on the refractory characteristics of ore. The leaching tests show that the extraction of gold and silver is consistently low, i.e. 47 and 19.2, respectively, over a leaching period of 24 h. Even fine grinding e.g. 38 m does not improve the recovery of gold and silver.
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