Factors affecting platinum extraction from used
In the present work, 13 iodine–iodide leaching tests were performed. The experimental conditions of these tests are reported in Table 2 . The tests were designed to study the effects of various factors, including catalysts size, agitation speed, solution pH, temperature and liquid to solid ratio on the Pt extraction rate and its maximum recovery.
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High-Pressure Oxidative Leaching and Iodide Leaching …
electronic equipment (EEE) and account for 3–6% of the total constitution of EEE [6,7]. ... and iodide leaching are described in this section. 2.2.1. Optimization of Iodide Leaching
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Release behavior of iodine during leaching and calcination …
The forms of the leached iodine were mostly ion-exchange and carbonate-bound iodine under pH 1.8 and water soluble and ion-exchange iodine under pH 3.8, 6.5, and 8.5. By calcination, the total iodine was released rapidly in 200-300 °C and 700-1000 °C, and almost released completely at 1000 °C, with a leaching rate of 96.6%.
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The leaching kinetics of an oxide gold ore with iodide/iodine …
Highlights Two gold ores were subjected to iodide/iodine leaching. The carbonaceous ore showed only 20% gold extraction. Gold extraction from the oxide ore reached 89% in 24 h. A power law rate equation was applied to model the gold extraction kinetics. Gold leaching rate was first order with respect to tri-iodide concentration.
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Kinetic modelling of chalcopyrite leaching assisted by iodine …
The kinetics of iodine-assisted chalcopyrite leaching in ferric sulfate media at ambient temperature were studied. A series of leaching tests were carried out to investigate the response of copper extraction from chalcopyrite to variations in the redox potential, total iodide concentration, particle size, and temperature.
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Refining the carbonate-associated iodine redox …
Our leaching experiments demonstrate that iodine is relatively stable in acidic solutions for ∼60 min, but nearly half of the iodine can be lost under prolonged …
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Iodine leach for the dissolution of gold
iodine leach processes are well known in the art, a significant problem with prior methods is that they suffer from inefficient recovery and reuse of iodine. Much of the iodine is consumed by the ore body. Since iodine is only 300 times more abundant than gold itself, this relative scarcity can make the use of iodine too expensive for commercially …
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Leaching characteristics of iodine in coal
By calcination, the total iodine was released rapidly in 200–300 °C and 700–1000 °C, and almost released completely at 1000 °C, with a leaching rate of 96.6%.
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(PDF) Estimation of Iodine Leaching in Soil Amended with
The model over predicted iodine leaching, results in a weak correspondence between the simulated and the measured results for iodine leaching. ... infiltration time, total leachate collected, and ...
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Iodine-Catalysed Dissolution of Elemental Gold in …
iodine–iodide leaching) or in organic solvents (c), which makes these methods less affordable. Expensive ligands in excess amounts (d) are ... [55–58] the total amount of thiols is dramatically reduced (Figure 1, d).[59] When dealing with complex metal mixtures, sequential dissolution seems like a realistic solution. By first removing the ...
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Determination of chlorine, bromine and iodine in plant …
Total organic iodine (TOI) is used as an integrative surrogate that reflects the amount of iodinated organics in a water sample and is quantified using a refined method that builds on previous ...
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Distribution, sources, and potential health risks of fluoride, total …
F-and TI were mainly derived from the leaching of fluoride- and iodine-containing minerals by cationic exchange, and NO 3-is mainly derived from nitrogen in the soil (31.7-43.9 %), the use of ammonia fertilizers (24.3-36.1 %), and the discharge of manure and sewage (19.4-31.9 %). Nitrogen in the soil can be an important source of nitrate in the ...
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Kinetic modelling of chalcopyrite leaching assisted by iodine …
To prevent iodine loss during leaching and sampling, a total of seven PTFE bottles with high chemical resistance were used to obtain one leaching curve, each representing one data point in the curve. The experimental results show that the copper extraction increased with increasing redox potential, increasing total iodide …
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Ion exchange recovery of gold from iodine–iodide solutions
1. Introduction. The use of a solution containing iodine–iodide as a lixiviant for gold was initially reported in various patents for recovering gold from scrap materials (Homic, 1976, Wilson, 1973).Later fundamental studies on this leaching system have been carried out by a number of researchers (Angelidis et al., 1993, Davis and Tran, 1991, …
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Iodine-assisted chalcopyrite leaching in ferric sulfate …
The measurement of the total iodide concentration at the beginning and end of a leaching test showed that the total iodide concentration did not change during leaching, meaning that the experimental apparatus was effective in preventing iodine loss via evaporation. 3.3. Effect of different parameters on iodine-assisted chalcopyrite …
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Release behavior of iodine during leaching and calcination of
The forms of the leached iodine were mostly ion-exchange and carbonate-bound iodine under pH 1.8 and water soluble and ion-exchange iodine under pH 3.8, 6.5, and 8.5. By calcination, the total iodine was released rapidly in 200-300 °C and 700-1000 °C, and almost released completely at 1000 °C, with a leaching rate of 96.6%.
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A Study of the Electrodeposition of Gold Process in Iodine Leaching
Authors: This paper mainly discusses electrodeposition of gold from iodine leaching solution through single-factor testing and explores the influence of gold concentration in catholyte, mass ...
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Speciation of iodine (127I and 129I) in lake sediments
The solution, containing extracted iodine, was separated from the sample by centrifugation. Iodine in the residue was extracted by alkali fusion in a ceramic crucible for one-time use, followed by water leaching [12]. An aliquot from each step was set aside for total iodine measurement.
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Iodine dynamics in soils
open access. Abstract. We investigated changes in iodine ( 129 I) solubility and speciation in nine soils with contrasting properties (pH, Fe/Mn oxides, organic carbon and iodine contents), incubated for nine months at 10 and 20 °C.
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Metals | Free Full-Text | High-Pressure Oxidative …
It suggests that iodide leaching is as much an effective method as iodine–iodide leaching for the extraction of gold from samples containing gold and can potentially reduce reagent cost, …
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Kinetic modelling of chalcopyrite leaching assisted by iodine …
A series of leaching tests was carried out in PTFE (polytetrafluoroethylene) bottles with high chemical resistance to investigate the effect of solution potential (673–769 mV vs SHE), total ...
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Metals | Free Full-Text | High-Pressure Oxidative Leaching and Iodide
This paper deals with the recovery of gold from waste printed circuit boards (WPCBs) ash by high-pressure oxidative leaching (HPOL) pre-treatment and iodide leaching followed by reduction precipitation. Base metals present in WPCB ash were removed via HPOL using a diluted sulfuric acid solution at elevated temperatures. Effects …
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Hydrometallurgical Recovery of Gold from Mining Wastes
Iodine gold leaching can be a promising alternative to cyanide leaching because of its low volatility and hazardousness . ... Science of The Total Environment. 1999; 242 (1-3):3-11. DOI: 10.1016/s0048-9697(99)00372-1; 17. Kinnunen PHM, Kaksonen AH. Towards circular economy in mining: Opportunities and bottlenecks for tailings …
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Recovery of platinum group metal value via potassium iodide leaching
For the untested materials the leaching process was able to achieve near total dissolution after approximately 20 min. Additionally the final dissolved Pt concentration was similar for each experiment with added iodine, indicating that the dissolution process for 0 mM may have been oxidant limited.
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Leaching of organic matter and iodine, formation of …
Leaching of organic matter and iodine, formation of iodinated disinfection by-products and toxic risk from Laminaria japonica during simulated cooking ... The dominant organic matter in Haidai leachate were polysaccharides, while the highest iodine specie was iodide (∼90% of total iodine). Several unknown I-DBPs generated from the ...
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Iodine Leaching Solution
Iodine leaching of gold is a kind of halogen gold extraction method. The stability of the gold iodine complex formed by leaching of the gold reaction ranks only second to the gold cyanide complex [1], and the ligand in the leaching of the gold system remains stable in the range of 0–14 [2]. Hence, this method is expected to replace gold ...
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Release behavior of iodine during leaching and …
By calcination, the total iodine was released rapidly in 200–300 °C and 700–1000 °C, and almost released completely at 1000 °C, with a leaching rate of 96.6%. …
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Release behavior of iodine during leaching and …
By calcination, the total iodine was released rapidly in 200-300 °C and 700-1000 °C, and almost released completely at 1000 °C, with a leaching rate of 96.6%.
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Iodide Pressure Oxidation Gold Leaching
The fundamentals of such an iodine leaching at ambient temperature was studied. However, the investigation on the dissolution behavior of gold in iodide solutions at elevated temperatures, such as the case in the system considered here has not yet been reported. ... One piece of high-purity gold square plate with total surface area of 2.95 …
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Estimation of Iodine Leaching in Soil Amended with …
enhancement of iodine retention in soils is currently a major challenge, therefore, the practical purpose of the present study was to overcome the problem of iodine leaching from soils. Research reports on the leaching and movement of iodine in soil supplemented with amendment materials using the HYDRUS-1D tool are scanty. The …
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