American Barrick operates two autoclaves for the processing of refractory gold ores. Because of the mineralogy of the ores, one autoclave is alkaline and the other acidic. The pH of operation has a significant effect on materials of construction, as well as capital and operating costs. The following summary concentrates on the practical and economic aspects of such operations.
Alkaline pressure oxidation is an effective pretreatment for releasing refractory gold from arsenical concentrates prior to cyanidation. alkaline conditions permit the use of
The oxidation of refractory gold concentrates containing arsenopyrite and pyrite and the simultaneous dissolution of gold in aerated alkaline solutions at ambient temperatures and pressures without the addition of cyanide has been studied. it involves the following aspects the chemistry of the oxidation of pure arsenopyrite and pyrite minerals in aerated alkaline solutions the kinetics of ...
Leaching and recovery of gold from mildly refractory ore in glycine media was investigated. temperature and ph have a substantial role in gold dissolution. 90 of gold extracted into the glycine solution after 24 h of leaching. 100 gold recovery from solution could be achieved by carbon adsorption within 4 h.
May 01, 2020nbsp018332a refractory bio-oxidised product, obtained from the ghanaian gold province, was employed in this study. our previous comprehensive characterisation studies showed that the sample as-received is highly refractory due to presence of intractable secondary sulphate minerals gypsum, jarosite - fig. 1, and secondly by inherent carbonaceous matter asamoah et al., 2018a asamoah et
The concentrate from the flotation procedure was processed using different preoxidation methods. a concentrate containing 34.08gt of gold with the gold recovery ratio of 81.20 was obtained by flotation. after roasting, microwave heating or alkaline pressure oxidation, the gold cyanidation ratio reached 82.37, 81.26 and 71.09 respectively.
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The nigerian federal government has now identified commercial deposits of a total of 37 minerals. some of these minerals include talc, gypsum, iron ore, lead, zinc, bentonite, baryte, gold . get price map of mineral deposits in nigeria - shibang-china.com. coal mining processing plant in nigeria.
Refractory gold ores are those that do not yield high gold recoveries in conventional cyanide-leaching circuits, even when the ore is finely ground. ... determined by the reaction conditions which range from mild in alkaline leaching and biological leaching to the aggressive conditions found in pressure oxidation. the gold and sulphur sulphides
Alkaline oand idation refractory gold - jainindia. alkaline pressure oxidation of a gold-bearing today the treatment of refractory gold ores and concentrates is. . oand idation of alcohols by mno2 with ball mill. get price and support online effect of mechanochemical activation on surface .
A gold recovery pretreatment process is disclosed in which the gold content is more completely extracted from refractory sulfidic ores which contain large quantities of metal carbonates such as dolomite than occurs in traditional gold extraction methods. the process includes treating the ore in an autoclave at elevated temperature and oxygen overpressure conditions in the presence of soda ash ...
Jan 01, 2004nbsp018332the alkaline oxidation of refractory gold concentrates containing arsenopyrite and pyrite at ambient temperatures and pressures has been found to be accompanied by the simultaneous dissolution of gold without the addition of cyanide. a detailed study has been made of the kinetics of the oxidation of the pure minerals and of several concentrates.
Alkaline pressure oand idation of gold concentrates. oxidation of refractory gold concentrates and simultaneous dissolution of gold in aerated alkaline solutions by suchun zhang b. eng. appl. chem., tsinghua university, beijing, china get price alkaline pressure oxidation of a goldbearing .
Keywords refractory gold concentrate hypochlorite ox idation pretreatment pressure cyanidation . 1. introduction . 1.1. background . many of the gold deposits contain finely disseminated gold in iron sulfide minerals such as pyrite and arsenopy- rite. such deposits are called refractory gold ores due to
Ammonia. the leaching experiments also have shown that gold may dissolve in alkaline thioarsenite solutions, which provides a possible new process option for the leaching of gold. the oxidation of refractory arsenical gold concentrates in aerated alkaline solutions results in the formation of thiosulfate, arsenate and sulfate as well as the
Emissions and is suitable for small gold producers. demopoulos and papangelakis have reviewed the recent development of hydrometallurgical oxidation processes and their possible applications to treat refractory gold ores 5. these processes can be classified as pressure oxidation 6, biological oxidation 7, and chemical oxidation 8.
Where the main gold bearing refractory mineral in the concentrate is pyrite, the oxidative leach is typically carried out under alkaline conditions. the leach conditions are set to ensure the formation of goethite as the major iron reaction product. the alkaline leach conditions accelerate the rate of
Jun 01, 1992nbsp018332a number of trials on pressure alkaline oxidation of gold ores have been reported in the ussr 10-12 . one reports gold recoveries from 98.2 to 99.6 after cyanidation of the products ofautoclave oxidation in naoh solutions, at 373-393 k l0 . the technique was tested with various concentrates assaying 8.9-621 gt of gold.
Oxidation of a refractory gold concentrate souza and. ciminelli, 1992. ... idation in carbonate-buffered solution 2. ... these results indicate that alkaline leaching could be a viable method ...
Technology is not used to leach the gold but only to make the cyanide ions accessible to the gold in the host mineral. 2. extraction of gold and silver from the argentopyrite argentite ore 2.1 pressure oxidation cyanidation chemistry the oxidation of gold and silver is a prerequi site for its dissolution in the alkaline
It was also found that pretreatment only in highly alkaline media ph gt 13 can be effective in gold recovery. gold and silver extractions during subsequent cyanidation were improved from 69.4 to 80.7 for gold and 44.4 to 88.9 for silver, where the extraction yields of arsenic, iron, and zinc were 93.7, 75.9, and 26.9, respectively.
Four iron-sulphide-containing gold ores from the white mountain mine in the jilin province, china were studied to examine the benefits of using oxidative treatment prior to conventional cyanidation to leach gold. this pre-treatment consisted of bubbling air into an orewater mixture for eight hours while adding enough caustic sodium hydroxide to maintain a ph of 11 throughout the test. three ...
The technological mineralogy of a gold deposit located in north-western province of zambia was carried out by using x-ray fluorescence spectroscopy xrf, x-ray diffraction spectroscopy xrd, and scanning electron microscope sem. the results showed that gold was highly dispersed in gold-bearing minerals such as pyrite, arsenopyrite, and some gangues in the form of natural gold and electrum.
Santa fe pacific gold corp. conducted pressure-oxidation pilot plant studies on refractory carbonaceous gold ores from the twin creeks mine in nevada. the tests were conducted at