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Cyanide Gold Extraction Process - JXSC Machine

Cyanide Gold Extraction Process Influencing Factors Slurry pretreatment The gold ore cyanide leaching pulp contains a certain amount of Fe2+, Cu2+, Zn2+, S2-, Fe3+ plasma, in addition to the metal sulfide mineral pyrite, pyrrhotite, chalcopyrite and sphalerite.

INFLUENCE OF PRE-AERATION ON CYANIDE LEACHING OF A …

between gold and silver extractions and cyanide consumption. Ninity five Au % and 88.0% Ag extractions were obtained under the determined conditions of 24 h leaching duration, -74 µm particle size, ... minerals like pyrrhotite. In another study, Jeffrey and Breuer (2000) investigated the

CHAPTER 3 COMPARISON OF DIFFERENT PYRRHOTITE …

COMPARISON OF DIFFERENT PYRRHOTITE DEPRESSANTS IN PENTLANDITE FLOTATION 3.1 INTRODUCTION Due to the similarities in mineralogy and chemical composition, and as well as the pyrrhotite collectorless flotation, it is difficult to achieve a clean separation between pentlandite and pyrrhotite. Pyrrhotite rejections has been a long-standing problem ...

Effect of Cyanide on Steel and How Iron Minerals are ...

The corrosion of black rolled mild steel in sodium cyanide solution is negligible. A piece of steel suspended in a sodium cyanide solution maintained at 0.05% NaCN and 0.001% CaO, in the presence of air, lost 0.002% of its weight in two weeks, this was equivalent to a penetration of 0.76 micron per year.Oxidized iron minerals such as hematite, magnetite, goethite, siderite and the silicate ...

Environmental & Health Effects | International Cyanide ...

This document is a general summary of cyanide's effects on human health and the environment, and is not intended to be a complete reference on all the environmental and health effects of cyanide. Human Health Effects Cyanide is produced in the human body and exhaled in extremely low concentrations with each breath. It is also produced by over 1,000 plant species including sorghum, bamboo and ...

Process simulation and gate-to-gate life cycle assessment ...

Dec 26, 2019· One of the prevailing challenges in cyanidation is related to impurities such as copper and reactive sulfides such as pyrrhotite. Copper forms stable cyanocomplexes, which increase the consumption of sodium cyanide in the process (Marsden and House 2006).Pyrrhotite and other sulfides can lead to high oxygen requirements due to the oxidation reactions of Fe 2+ to Fe 3+ and …

Gold Metallurgy & Leaching in Cyanicides

The reason for the lower cyanide consumption obtained with intense aeration is probably connected with the reactions which take place when alkaline sulphide decomposes in cyanide solution. Alkaline sulphide is one of the initial products of the reaction between pyrrhotite and alkaline cyanide solution.

phyrrotite cyanidation effect - lindenbos.be

The effect of the metal to sulphur ratio in the nonstoichiometic compound, pyrrhotite, is related to the consumption of cyanide in gold leaching. Reactive pyrrhotite (Fe (I-X) S) is produced during the pyrolysis of refractory pyrite (FeS 2). Iron vacancies give pyrrhotite its non stoichiometric nature and determine its fugacity and hence ...

Emerging technologies in cyanidation of gold and silver: a ...

improved cyanide consumption, leaching kinetics as well as overall gold extraction. Pretreatment with lead nitrate and low DO produced fast leaching kinetics, low cyanide consumption and high extraction of gold for the Eleonore pyrrhotite concentrate. Aurostibite, …

(PDF) Cyanidation of a pyrrhotite-bearing gold ore

Samples that were partially converted to pyrrhotite, and hence remained in equilibrium with the unconverted pyrite, showed an increase in cyanide consumption with increasing metal to sulphur ratio.

The effect of sulfide minerals on the leaching of gold in ...

It was reported that pre-leaching successfully overcame the effect of pyrite and pyrrhotite on cyanide consumption and the gold leaching kinetics, but it had no beneficial effect when chalcopyrite was present. It was suggested that lead nitrate prevented copper and iron dissolution by forming a passive layer at the surface of sulfide minerals.

Rcovery of gold in pyritic ores - Mine Engineer.Com

Using cyanide to recover gold from sulfide ores generally results in 30 to 35% recovery, and the best I have heard of is around 50% recovery. The fine coating of a iron compound definitely appears to be a key component of the inability of cyanide to efficiently leach low grade pyritic ores.

The problems caused by iron ... - International Mining

If this is not done, it is very difficult to maintain a pH of >10, which is needed to maintain cyanide in the free cyanide form rather than the toxic, gaseous HCN form. The pH constantly drifts downwards due to the slow consumption of lime by basic iron sulphate, which leads to the formation of HCN gas, and creates an unsafe working environment ...

v118n5a2 Test work to examine the potential for improving ...

increase in cyanide consumption. The introduction of lead nitrate resulted in a 34 g/t decrease in cyanide consumption. According to La Brooy, Linge, and Walker (1994), reactions involving sulphides may consume cyanide and oxygen and produce various solution species that can decrease the efficiency of gold leaching. Pyrrhotite is the most ...

Cyanidation of a pyrrhotite-bearing gold ore

1995). The transformation of pyrite to pyrrhotite, using pyrolysis, indicated that the cyanide consumption gradually decreases with an increase in the pyrrhotite content of the sample (Browner and Lee, 1998). This finding means that pyrrhotite is less reactive than pyrite in a cyanide solution. The reactivity of pyrrhotite * Corresponding author.

Improved leach recovery - IsaMill™ Advantages | Isamill

Pre-aeration increases the Eh and oxidises the active pyrite and pyrrhotite to reduce cyanide consumption in the leach process. This is different from the patented Albion Process, where significant portions of sulphides (over 10%) are oxidised by atmospheric leaching to increase metal recovery.

Kibali Gold Mine sulphide concentrate treatment ...

cyanide consumption; and (iv) stage dissolution or residue values achieved. Lime and cyanide consump- ... the ore body with a predominantly pyrrhotite min-eralisation. Cyanide and lime consumption are reported in kg/t of concentrate with typicalflotation mass pulls of between 10 and 11%. Under these

INFLUENCE OF LEAD NITRATE ON CYANIDE LEACHING OF …

the dissolution of metallic sulfides, thus reduces cyanide consumption (Deschenes et al., 2003). Metallic sulfides such as pyrite, chalcopyrite and pyrrhotite show different reaction mechanisms with lead nitrate. Lead nitrate passivizes the pyrite by forming a hydroxide (Pb(OH) 2

Cyanide Leaching Chemistry & Gold Cyanidation

Cyanide Leaching Chemistry & Gold Cyanidation. Previous Next ... Not only do copper minerals dissolve in cyanide and cause excessive consumption of this chemical, but also, the copper cyanogen complexes thus formed indirectly affect the dissolution of the gold. ... whereas a difference in the pyrrhotite content of the ore might affect seriously ...

Gold with Pyrite, Pyrrhotite, Marcasite and Arsenopyrite ...

Apr 17, 2016· Pyrite is the most stable but when pyrrhotite is present trouble is usually experienced both in regard to cyanide consumption and gold extraction. Pyritic flotation concentrates are often reground for gold liberation before cyanidation as at Itogon-Suyoc Itogon, and Pamour.

Advances in the Cyanidation of Gold - ScienceDirect

Gold was present as native gold and electrum. A test conducted at 2000 ppm NaCN and pH 11.0 produced 97.0% extraction of gold in 72 h. It was found that an efficient leaching required only 3–5 ppm DO. However, the presence of reactive pyrrhotite resulted in a cyanide consumption …

Kinetic gold leach monitoring including J cyanide speciation

pyrrhotite are some of the most common. The first cyanidation plant in the world was ... cyanide species, arsenic, certain metals and sulphur species) ... reagent consumption, discharge control and amelioration-specific measures. Practically, it would be unrealistic to affect ...

Cyanide Leaching and Decomposition of Pyrrhotite

Optimum results as regards gold extraction and cyanide consumption are obtained when using well aerated cyanide solutions containing at least 0.05% CaO and saturated with calcium sulphate. Laboratory results showing the cyanicidal effects of pyrrhotite under various conditions were given.