Results 251 to 260 of about 832,680 (294)

Gold Leaching in an Alkaline Thiourea Solution

Journal of The Electrochemical Society, 1999
Gold leaching by thiourea has been investigated in an alkaline solution. In the presence of both Na 2 SO 3 and Na 2 S 2 O 8 , the chemical dissolution of gold can be accomplished in the alkaline thiourea solution. It was found that used as a buffer, SO 2- 3 can prevent thiourea from further decomposing into some insoluble species in contact with the
Dawei Wei, Liyuan Chai, Ryoichi Ichino, Masazumi Okido   +3 more
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Effect of hematite on thiosulphate leaching of gold

International Journal of Mineral Processing, 2007
Abstract Hematite, as a typical iron oxide slime in sulphide ore slurries, was artificially added into the leaching systems of pure gold and a sulphide ore respectively, in an attempt to investigate the effect of iron oxide slimes on the ammoniacal thiosulphate leaching of gold.
D. Feng, J.S.J. van Deventer
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A study of the leaching of gold and silver by acidothioureation

Hydrometallurgy, 1980
Abstract The method of thiourea leaching for the extraction of gold and silver from ore in acidic medium was studied. The effect of various amounts of oxidant was also investigated. It was found using a rotating disk experiment that when the leaching solution contained 1.0% thiourea, 0.5% sulfuric acid and 0.1% ferric ions, the rate of gold and ...
C.K. Chen, T.N. Lung, C.C. Wan
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The role of oxygen in thiosulphate leaching of gold

Hydrometallurgy, 2007
Abstract The role of oxygen in thiosulphate leaching of gold has been investigated in both pure gold and ore systems. The gold dissolution decreased in the presence of oxygen in the pure gold system. Air or oxygen bubbling caused higher consumption of thiosulphate and leaching passivation. Nitrogen bubbling largely increased gold dissolution and this
D. Feng, J.S.J. van Deventer
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Alternative Leaching Reagents for Gold

1991
Sodium cyanide has been the preponderant leaching reagent for gold due to its excellent extractions from a great variety of ores and its low cost. Although cyanide is poisonous, it has safe industrial and environmental records at the high pH range required in cyanide leaching. In addition, the low concentrations of cyanide used in gold milling and heap
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Thiourea–thiocyanate leaching system for gold

Hydrometallurgy, 2011
Abstract The leaching of gold in thiourea–thiocyanate solutions has been studied by the rotating-disc technique using ferric sulfate as oxidant. The effects of initial concentrations of ferric, thiourea (Tu) and thiocyanate as well as temperature and pH on gold leaching rates were studied. An initial gold leaching rate in the order of 10− 9 mol cm− 2 
Xiyun Yang, Michael S. Moats, Jan D. Miller, Xuming Wang, Xichang Shi, Hui Xu   +5 more
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The intensive Leaching of Gold Concentrates Containing Cyanicides [PDF]

The recovery of gold via a gravity circuit is a beneficial and economical process to all operating plants. However the efficiency in this circuit is an important factor to consider. The intensive cyanidation process for treating gravity concentrates is becoming more favourable in the gold processing industry today.
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Improvement of thiosulfate stability in gold leaching

Mining, Metallurgy & Exploration, 2003
Ammonium thiosulfate is a noncyanide lixiviant for gold leaching. However, the major problem with this leaching method has been the high consumption of reagents. To leach a mild-refractory copper-bearing gold ore, the authors used a reagent combination of 0.3M (NH 4 ) 2 S 2 O 3 , 0.03M CuSO 4 and 3M NH3 at pH 10.2 for 24 hours.
C. Xia, W. T. Yen, G. Deschenes
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Prospects for underground leaching in gold mines

Journal of Mining Science, 2016
The authors describe experiments on pretreatment of ore by injection of explosive gases before underground leaching of gold in mine conditions. It is shown that injection of explosive gases into opening micro-fractures enhances efficiency of underground leaching owing to microstructural transformation of ore containing dispersed gold.
A. G. Sekisov, Yu. S. Shevchenko, A. Yu. Lavrov   +2 more
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Iodide—thiocyanate leaching system for gold

1994
The leaching of gold by thiocyanate solutions is performed at pHs between 1 and 2, which allows the use of iron(III) as an oxidizing agent. The mechanism of dissolution of gold by iron(III)-thiocyanate solutions is directly linked with the autoreduction process, in which FeIII is spontaneously reduced to FeII while oxidizing SCN- This oxidation ...
O. Barbosa-Filho, A. J. Monhemius
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