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HGT Hydraulic Gyratory Crusher

HGT Hydraulic Gyratory Crusher

HGT Gyratory Crusher is a new-type intelligent coarse crusher with big capacity and high efficiency. It integrates mechanical, hydraulic, electric, automated, and intelligent controlling technologies which grant it with advantages traditional crushing

European Type Jaw Crusher PEW

European Type Jaw Crusher PEW

Jaw crushers has stationary jaw crusher, portable jaw crusher and mobile jaw crusher (crawler jaw crusher). Jaw crusher (PEW Series) is not only able to be used together with mine-selecting and gravel processing equipments but also be used independen

Jaw Crusher PE

Jaw Crusher PE

Jaw crusher is driven by a motor, and the moving jaw moves up and down via eccentric shaft. The angle between fixed jaw and moving jaw becomes smaller when the moving jaw runs down, then the materials are crushed into pieces. It will become bigger whe

HPT Hydraulic Cone Crusher

HPT Hydraulic Cone Crusher

Base on the latest technology and decades of years’ producing experience, Our Company designed the HPT series cone crusher. It has excellent crushing efficiency and good hydraulic control system. Now the HPC series cone crusher has wide application

HST Hydraulic Cone Crusher

HST Hydraulic Cone Crusher

HST Single Cylinder Hydraulic Cone Crusher is a new high-efficiency cone crusher independently researched, developed and designed by SBM through summarizing over twenty years of experience and widely absorbing advanced American and German technologies

CI5X Series Impact Crusher

CI5X Series Impact Crusher

CI5X Impact Crusher breaks materials with impact force. When materials enter the working area of hammer, they may be crushed under the high-speed shock and then thrown onto the impact device above the rotor for another crushing. Next, materials bounce

VSI6X Series Vertical Crusher

VSI6X Series Vertical Crusher

Due to the increasing market demand for the scale, intensification, energy conservation, environment protection and high-quality machine-made sand, SBM, a Chinese professional sand maker manufacturer, further optimizes the structure and function of tr

VSI5X Vertical Shaft Impact Crusher

VSI5X Vertical Shaft Impact Crusher

VSI Crushers Working Principle Raw material falls down into feed hopper, and then enters rotor through central entrance hole. It is accelerated in high-speed rotor, and then is thrown out at speed of 60-75m/s. When hitting anvil, it is crushed. Final

VSI Vertical Shaft Impact Crusher

VSI Vertical Shaft Impact Crusher

VSI Series vertical shaft impact crusher is designed by reputed German expert of SBM and every index is in worlds leading standard. It incorporates three crushing types and it can be operated 720 hours continuously. Nowadays, VSI crusher has replaced

VUS aggregate optimization system

VUS aggregate optimization system

The VU system is a global most-advanced dry-process sand-making system. The system is constructed like a tower. Its fully-enclosed layout features high integration. It integrates the functions of high-efficiency sand making, particle shape optimizatio

MTW-Z European Trapezium Mill

MTW-Z European Trapezium Mill

MTW European Grinding Mill is innovatively designed through deep research on grinding mills and development experience. It absorbs the latest European powder grinding technology and concept, and combines the suggestions of 9158 customers on grinding m

5X Series Roller Grinding Mill

5X Series Roller Grinding Mill

Grinding roller of MB5X Pendulum Roller Grinding Mill l adopts diluted oil lubrication. It is a technology initiated domestically which is maintenance-free and easy to operate. Diluted oil lubrication is oil bath lubrication, more convenient than grea

MTW Trapezium Mill

MTW Trapezium Mill

MTW European Grinding Mill is innovatively designed through deep research on grinding mills and development experience. It absorbs the latest European powder grinding technology and concept, and combines the suggestions of 9158 customers on grinding m

LM Vertical Mill

LM Vertical Mill

LM Vertical Grinding Mill integrates crushing, drying, grinding, separating and transport. The structure is simple while the layout is compact. Its occupational area is about 50% of that of the ball-milling system. The LM grinding mill can also be arr

TGM Trapezium Mill

TGM Trapezium Mill

TGM Super Pressure Trapezium Mill The operation principle of main unit of Trapezium mill is that main unit runs with the central shaft that is driven by a gear box. The top of the shaft is connected with a quincunx stand on which a grinding roller is

Elsner Equation On Gold Leaching

Aachen Reactors - Application 1. Cyanide leaching of gold ...

A generally accepted mechanism is described by the Elsner equation. 4Au + 8NaCN + O 2 + 2H 2 O = 4NaAu (CN) 2 + 4NaOH Elsner’s Equation shows oxygen as a requirement for the gold leach reaction – how much is still under debate. The above equation shows a cyanide to oxygen ratio of 8:1.

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The Metallurgy of Cyanide Gold Leaching – An Introduction ...

20/10/2014  A paper published by L. Elsner in 1846 first correctly identified the chemical reaction that forms the basis of all gold cyanide leaching processes: 4 Au + 8 NaCN + O 2 + 2 H 2 O → 4 Na [Au (CN) 2] + 4 NaOH The equation is well known, but the successful application of this reaction in a gold mining operation is rarely straightforward.

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Intensive Cyanidation - Resources Gold Technology

Elsner Equation The Resources Intensive Cyanidation Reactor operates on a cyclic basis utilizing three tanks sequentially for filling and chemical dosing, followed by reaction time and discharge. Each of the tanks sequentially rotates in their function.

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Advances in the Cyanidation of Gold - ScienceDirect

01/01/2016  The most commonly used equation for the dissolution of gold in a cyanide solution, known as Elsner's equation, is (26.1) 4Au + 8NaCN + O2 + 2H2O → 4NaAu (CN)2 + 4NaOH Gold dissolution is an electrochemical reaction in which oxygen takes up electrons at one part of the metallic surface (the cathodic zone), while the metal gives them up at another (the anodic zone).

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Cyanide control in the metallurgical process of gold ...

and oxygen derived from Elsner’s equation: [1] From the Equation, it is apparent that both cyanide and oxygen are required in an aqueous solution in order to leach gold. For the leaching of pure gold, the stoichiometry of Elsner’s reaction gives the required molar ratio of free cyanide to oxygen as 8:1 (or 61/ 2:1 when expressed as a mass ratio). Since cyanide is the more expensive reagent ...

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Oxygen Generation Plant for Gold Leaching

soluble aurocyanide complex according to the Elsner Equation: 4 Au + 8 NaCN + O 2 + 2H 2 O - 4 NaAu(CN) 2 + 4 NaOH A slurry of the ground ore is mixed with cyanide in the presence of activated carbon. The carbon has a very high affinity for the aurocyanide complex and adsorbs the gold out of solution resulting in very high loadings on the carbon (typically 1000 – 4000 g/t). At the end of the ...

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Intensive cyanidation: onsite application of the InLine ...

for the leaching of gold is known as Elsner's equation, Lenahan et al., 1986: Oxygen is an indispensable reagent in the reaction and is provided either from atmospheric oxygen, hydrogen peroxide or a production oxygen facility, McQuiston, 1985. The level of oxygen addition required is deter- mined from the initial test work and/or during plant commissioning. Fig. 3 shows leach profiles for ...

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elsner equation on gold leaching - UnityOne

Elsner Equation On Gold Leaching - Fattoria Prattico Elsner’s equation is generally accepted as expressing the action of gold in dilute cyanide solutions; 4 Au

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Chemistry of Cyanidation of Gold Silver

05/09/2016  Metallurgical ContentHow does Cyanide Leach Silver SulphideWhat is the Function of Oxygen in cyanidationCyanide Reducing AgentsEffect of Temperature on cyanide leachingDissolving Effect of Zinc-potassium CyanideFouling of Cyanide SolutionsStrength of Solution in CyanideSources of Cyanide LossThe Use of Lead SaltsPremature PrecipitationCyanide RegenerationRelative Dissolving

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Advances in the Cyanidation of Gold - ScienceDirect

01/01/2016  The most commonly used equation for the dissolution of gold in a cyanide solution, known as Elsner's equation, is (26.1) 4Au + 8NaCN + O2 + 2H2O → 4NaAu (CN)2 + 4NaOH Gold dissolution is an electrochemical reaction in which oxygen takes up electrons at one part of the metallic surface (the cathodic zone), while the metal gives them up at another (the anodic zone).

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Cyanide control in the metallurgical process of gold ...

and oxygen derived from Elsner’s equation: [1] From the Equation, it is apparent that both cyanide and oxygen are required in an aqueous solution in order to leach gold. For the leaching of pure gold, the stoichiometry of Elsner’s reaction gives the required molar ratio of free cyanide to oxygen as 8:1 (or 61/ 2:1 when expressed as a mass ratio). Since cyanide is the more expensive reagent ...

More

Oxygen Generation Plant for Gold Leaching

soluble aurocyanide complex according to the Elsner Equation: 4 Au + 8 NaCN + O 2 + 2H 2 O - 4 NaAu(CN) 2 + 4 NaOH A slurry of the ground ore is mixed with cyanide in the presence of activated carbon. The carbon has a very high affinity for the aurocyanide complex and adsorbs the gold out of solution resulting in very high loadings on the carbon (typically 1000 – 4000 g/t). At the end of the ...

More

Intensive cyanidation: onsite application of the InLine ...

for the leaching of gold is known as Elsner's equation, Lenahan et al., 1986: Oxygen is an indispensable reagent in the reaction and is provided either from atmospheric oxygen, hydrogen peroxide or a production oxygen facility, McQuiston, 1985. The level of oxygen addition required is deter- mined from the initial test work and/or during plant commissioning. Fig. 3 shows leach profiles for ...

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New Technology for Recovery of Gold and Silver by Pressure ...

The dissolution of the gold can be written as in Equation (19), where oxygen is the oxidant and thiosulphate is the ligand. 4 Au + 8S2O32-+ O2+ 2H2O D 4[Au(S2O3)2]3-+ 4OH-(19) Fig. 1. Schematic mechanism of gold and silver leaching.

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Use of ferricyanide for gold and silver cyanidation ...

01/06/2009  The well-known Elsner equation (1946) describes the stoichiometry of the reactions as follows : 4Ag+8CN +O2+2H2O= 4Ag (CN) 2 +4OH 4Au+8CN +O2+2H2O= 4Au (CN) 2 +4OH (1) (2) hydrogen peroxide (H2O2), calcium peroxide (CaO2), and per-manganate (KMnO4) for gold and silver cyanidation process has been proposed with the purpose of increasing gold and silver dissolution rate

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Use of ferricyanide for gold and silver cyanidation

Elsner equation (1946) describes the stoichiometry of the reactions as follows[1]: ... potentially increase gold leaching rate. The catalytic function of ferricyanide on gold/silver cyanidation has been reported[10−11]. The half reaction between the dissolved iron-cyanide species can be expressed as 3− Fe(CN)6 +e= 4− Fe(CN)6 , φ 0=0.36 V (vs SHE) (3) Though the standard reduction ...

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Processing Gold Ores Using Heap Leach-Carbon Adsorption ...

The reaction (Elsner's equation) generally accepted for several decades as representing the dissolution of gold by cyanide solution is Recent research on the mechanism of cyanidation, however, indicates this reac- tion proceeds in two stages (1, p. 305). Most of the gold dissolves by the react ion and a small but significant proportion dissolves via reaction 1. The gold dissolution rate is ...

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Tubular Reactor - Resources Gold Technology

In many gold leaching applications pipe reactors also use Hydrogen Peroxide (H2O2) and O 2 to react with sulfides and other minerals helping liberate gold and enhance the leaching process within the tubular reactor. 4 Au + 8 NaCN + O2 + 2 H2O → 4 Na [Au (CN)2] + 4 NaOH

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(PDF) The Use of Oxygen in Gold Cyanidation Wesley ...

This equation retains all the basic features of the rate equations that have been proposed in the literature for gold ore leaching and makes an effort to decouple the effects of [C'N ] and [O,] from the rate constants. The successful combination of electrochemistry and kinetics in a generalized rate equation by Wadsworth [I I] has been an important progression in the cyamde leaching studies of ...

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Cyanide control in the metallurgical process of gold ...

and oxygen derived from Elsner’s equation: [1] From the Equation, it is apparent that both cyanide and oxygen are required in an aqueous solution in order to leach gold. For the leaching of pure gold, the stoichiometry of Elsner’s reaction gives the required molar ratio of free cyanide to oxygen as 8:1 (or 61/ 2:1 when expressed as a mass ratio). Since cyanide is the more expensive reagent ...

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Choosing The Sepro Leach Reactor for Your Gold Recovery ...

Gold leaching follows the Elsner Equation: 4 Au(s) + 8 NaCN(aq) + O 2 (g) + 2 H 2 O(l) -> 4 Na[Au(CN) 2](aq) + 4 NaOH(aq). Cyanide concentrations of around 60ppm (parts per million) are added to slurry mixtures to dissolve the gold in a standard cyanidation circuit. For gravity concentrate with very high gold concentrations, intensive cyanidation (20,000 ppm) is used. Due to the limited amount ...

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New Technology for Recovery of Gold and Silver by Pressure ...

Leaching and Electrocoagulation José R. Parga 1, ... The Equation (1) proposed by Elsner is stoich iometrically correct but does not describe the cathodic reactions associated with the dissolution. The stoichiometry of t he process shows that 4 moles of cyanide are needed for each mole of oxygen used. At room temperature and std. atmospheric pressure, approximately 8.2 mg of oxygen are ...

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Cyanide Chemistry International Cyanide Management Code ...

The process of extracting gold from ore with cyanide is called cyanidation. The reaction, known as Elsner's Equation, is: 4 Au + 8 CN-+ O 2 + 2 H 2 O = 4 Au(CN) 2-+ 4 OH-Although the affinity of cyanide for gold is such that it is extracted preferentially, cyanide will also form complexes with other metals from the ore, including copper, iron and zinc. The formation of strongly bound complexes ...

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Intensive cyanidation: onsite application of the InLine ...

for the leaching of gold is known as Elsner's equation, Lenahan et al., 1986: Oxygen is an indispensable reagent in the reaction and is provided either from atmospheric oxygen, hydrogen peroxide or a production oxygen facility, McQuiston, 1985. The level of oxygen addition required is deter- mined from the initial test work and/or during plant commissioning. Fig. 3 shows leach profiles for ...

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Reaction Equation Of Separating Gold In Sodium Cyanide

Elsner Equation On Gold Leaching. Cyanide Chemistry International Cyanide 201975 183 The process of extracting gold from ore with cyanide is called cyanidation The reaction known as Elsners Equation is 4 Au 8 CN O 2 2 H 2 O 4 AuCN 2 4 OHAlthough the affinity of cyanide for gold is such that it is extracted preferentially cyanide will also form complexes with other metals from the ore including ...

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Use of ferricyanide for gold and silver cyanidation

Elsner equation (1946) describes the stoichiometry of the reactions as follows[1]: ... potentially increase gold leaching rate. The catalytic function of ferricyanide on gold/silver cyanidation has been reported[10−11]. The half reaction between the dissolved iron-cyanide species can be expressed as 3− Fe(CN)6 +e= 4− Fe(CN)6 , φ 0=0.36 V (vs SHE) (3) Though the standard reduction ...

More

Tubular Reactor - Resources Gold Technology

In many gold leaching applications pipe reactors also use Hydrogen Peroxide ... Elsner Equation . The tubular reactor is fed with gold ore slurry, flotation concentrate or refractory gold ore via a high pressure slurry pump. A heat exchanger is used to start and maintain the thermal reaction within the pipe reactor. H 2 O 2 and O 2 are added sequentially at specific points to enhance the ...

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(PDF) The Use of Oxygen in Gold Cyanidation Wesley ...

This equation retains all the basic features of the rate equations that have been proposed in the literature for gold ore leaching and makes an effort to decouple the effects of [C'N ] and [O,] from the rate constants. The successful combination of electrochemistry and kinetics in a generalized rate equation by Wadsworth [I I] has been an important progression in the cyamde leaching studies of ...

More

Cyanide Leaching Chemistry Gold Cyanidation

The reactions that take place during the dissolution of gold in cyanide solutions under normal conditions have been fairly definitely established. Most agree that the overall cyanide equation for leaching and cyanidation of gold is as follows: 4 Au + 8 NaCN + O2 + 2 H20 = 4 NaAu(CN)2 + 4 NaOH

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Gold_cyanidation - chemeurope

The chemical reaction is called the Elsner Equation as follows : 4 Au + 8 NaCN + O 2 + 2H 2 O → 4 Na Au (CN) 2 + 4 NaOH It is an electrochemical process in which oxygen picks up electrons from the gold at a cathodic area, whilst gold ions are rapidly complexed by the cyanide around the anodic area to form the soluble aurocyanide complex.

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MAXIMISING THE VALUE OF GOLD DIAGNOSTIC LEACHING

leaches with the dissolution of gold in aqueous cyanide solution taking place according to the Elsner equation in the presence of oxygen (8): ... The exact mechanism of these equations will vary according to the copper sulfide mineral and reaction conditions. 101 + − → 2− + 2− Cu x S y 3xCN x[Cu (CN )3] yS (2) Cu x S y H xCu yH 2 S + 2 + → 2+ + (3) This paper focuses on two commonly ...

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Choosing The Sepro Leach Reactor for Your Gold Recovery ...

Gold leaching follows the Elsner Equation: 4 Au (s) + 8 NaCN (aq) + O 2 (g) + 2 H 2 O (l) -> 4 Na [Au (CN) 2 ] (aq) + 4 NaOH (aq). Cyanide concentrations of around 60ppm (parts per million) are added to slurry mixtures to dissolve the gold in a standard cyanidation circuit.

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Reaction Equation Of Separating Gold In Sodium Cyanide

Elsner Equation On Gold Leaching. Cyanide Chemistry International Cyanide 201975 183 The process of extracting gold from ore with cyanide is called cyanidation The reaction known as Elsners Equation is 4 Au 8 CN O 2 2 H 2 O 4 AuCN 2 4 OHAlthough the affinity of cyanide for gold is such that it is extracted preferentially cyanide will also form complexes with other metals from the ore including ...

More

Cyanide Chemistry International Cyanide Management Code ...

The reaction, known as Elsner's Equation, is: 4 Au + 8 CN - + O 2 + 2 H 2 O = 4 Au (CN) 2- + 4 OH - Although the affinity of cyanide for gold is such that it is extracted preferentially, cyanide will also form complexes with other metals from the ore, including copper, iron and zinc.

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Barrick Thiosulfate Leaching of Double Refractory Ore

commonly found in gold bearing deposits, and can cause negative interactions with the cyanide leaching process. The effect of these negative interactions of the leaching process is shown in Eq.1. Eq. 1 is known as the Elsner Equation.9

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Selective Removal of Mercury from Gold Bearing Streams ...

A common technique for extracting gold from its ores is the cyanide process, wherein leaching of gold is achieved by the addition of cyanide at alkaline pH following the Elsner equation (Equation (i)) (1). Cyanide is a strong lixiviant for gold and so leaches the gold out of the ore into solution (2).

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Extraction of gold and silver at the Kupol Mill using CELP

two leaching regimes. The dissolution of gold and silver in a cyanide solution are a electrochemical reactions. Elsner’s equation illustrates the dissolution of gold according to: [1] Li and Wadsworth4 identified the following mechanisms: anodic dissolution of silver, cathodic reduction of oxygen and leaching of silver in cyanide solution ...

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(PDF) The Use of Oxygen in Gold Cyanidation Wesley ...

Elsner's equation [eqn (I)] illustrates the role of oxygen in gold cyanidation [S] : 4Au + 8NaCN + O2 + 2Hz0 e 4 [NaAu (CN),] +4 NaOH.

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Optimization of cyanidation parameters to increase the ...

So the Elsner Equation is achieved as below [1, 7]: 22 2 4 8 2 € 4 4Au CN O H O Au CN OH l (3) Some of the most effective parameters in cyanidation process are dissolved oxygen concentration, the free cyanide concentration, pH, particle size and operating conditions. The dissolved Oxygen concentration determines the cathode reduction of dissolved oxygen and may be supplied by air or pure ...

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