gold cyanidation reaction equation

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The Metallurgy of Cyanide Gold Leaching – An Introduction

20 Oct 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 O2 2 H2O → 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 nbsp

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Sodium cyanide Formula Structure MSDS Uses and Properties

The structure of potassium cyanide KCN is similar to that of NaCN The effects of both cyanide compounds are also identical Ingestion of KCN or NaCN can cause headache nausea dizziness and nervousness Extraction of gold can also be done using KCN through similar process In this reaction the resulting product is nbsp

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gold processing Britannica com

The oxidant employed is atmospheric oxygen which in the presence of an aqueous solution of sodium cyanide causes the dissolution of gold and the formation of sodium cyanoaurite and sodium hydroxide according to the so called Elsner reaction Chemical equation When gold dissolution is complete the gold bearing nbsp

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The Leaching of Gold in Cyanide Solutions in the Presence of

solves in aerated cyanide solutions to produce the gold cyanide com plex The stoichiometry by which this reaction occurs is known as the Elsner2 equation as shown here 4Au 8CN O2 2H2O r 4Au CN 2 4 OH 1 Although cyanidation chemistry is well established cyanidation kinetics are not It has been shown in nbsp

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Extraction of gold using cyanide NZQA

If the gold ore contains other metals and or sulphide minerals it may require additional treatments prior to the leaching process The treated gold then has sodium cyanide added to it and the following reaction known as Elsener 39 s equation occurs 4Au 8CN O2 2H2O ⇌ 4 Au CN 2 4OH In this form the gold is now nbsp

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The Effect of Increasing Capacity on Gold Recovery and

Based on these two reactions the following general reaction Elsner equation is achieved Marsden J I House 2006 4Au 8CN O2 2H2O 4Au CN 2 4OH Based on this equation the dissolution rate of gold metal is fourfold the rate of dissolved oxygen consumption and half the rate of cyanide consumption nbsp

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Gold Passivation in Aqueous Alkaline Cyanide CiteSeerX

the three anodic current peaks found in both steady state and potential sweep experiments resulted from passivation of the gold cyanide dissolution reaction to electron electron exchange and correlation and the multiple scattered wave method of solving SchrSd inger 39 s equation Details of the technique including

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Dynamic simulation of the carbon in pulp and carbon in leach

Note that under equilibrium conditions RCB 0 this model becomes the classical Langmuir equation where A Cc and B kd ka b Gold Cyanidation The kinetics of three phase reactions can be very complex however in many ore leaching systems the pseudohomogeneous approach has been sufficient to describe nbsp

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Patent US3989800 Alkali metal gold cyanide method Google

2 Nov 1976 This disclosure relates to a method for preparing alkali metal gold cyanide which has been found to be particularly useful in gold electroplating operations in the semiconductor industry in order to provide electrical contacts to semiconductor devices In the process finely divided gold metal particles are nbsp

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Gold leaching by organic base polythionates new non toxic and

7 Apr 2014 Keywords Polythionate Organic base polythionate Smolyaninov reaction Gold leaching Thiosulfate leaching Cyanide leaching equation image 8 This novel chemical reaction the Smolyaninov reaction was patented as a Method of obtaining organic base polythionates RU Patent No 2404948 nbsp

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Cyanide Leaching Of Gold

That presumes that the only elements are the gold Sodium Cyanide and water However as any geologist will tell you no two ores are the same and their chemical composition will vary greatly throughout the ore body These quot extra quot elements in the mineral compounds will often play havoc with a chemical reaction nbsp

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The Chemistry of the Extraction of Gold SAIMM

THE CHEMISTRY OF THE EXTRACTION OF GOLD is 4 93 x 10 10 a lowering of pH results in a reduction in the concentra tion of free cyanide ions The effect of this hydrolysis reaction can be incor porated into Equation 15 22 yielding E 0 53 0 059 log Au CN 0 118 log CNLot 2 Au CN 0 118 log 4 93 nbsp

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Gold 1 potassium cyanide 1 1 2 C2AuKN2 ChemSpider

Gold 1 potassium cyanide 1 1 2 Molecular FormulaC2AuKN2 Average mass288 100 Da Monoisotopic mass287 936340 Da ChemSpider ID140427 Charge Charge nbsp

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Gold I cyanide AuCN PubChem

PubChem CID 68172 Chemical Names Gold I cyanide Gold cyanide Au CN 506 65 0 Gold monocyanide MFCD00003437 EINECS 208 049 1 More Molecular Formula AuCN or CAuN Molecular Weight 222 985 g mol InChI Key IZLAVFWQHMDDGK UHFFFAOYSA N Safety Summary Laboratory Chemical nbsp

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Modelling and simulation of gold ore leaching Sono Dyne Inc

Cyanide concentration in solution Ore copper concentration dg Length of cubic gold grain sides dp Length of cubic ore particle sides Cyanide diffusivity 24 where mAup 0 is the mass of gold accessible through ore porosity at the beginning of the reaction and obtained by Equation 3 Cyanide consumption nbsp

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Kinetics and reaction mechanism of gold cyanidation Surface

Gold cyanidation has been reported to involve the chemical reactions shown in Eq 1 Bodländer 1896 and Eq 3 Elsner 1846 where Eq 3 can be treated as the sum of the two partial reactions shown in Eqs 1 and 2 Hydrogen peroxide produced at the interface by reduction of oxygen can react with gold Eq 2 nbsp

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Co intensification of cyanide leaching gold by mercury ions and

process 1−2 in which the anodic reaction is gold oxidation and formation of Au CN− 2 while the cathodic reaction is oxygen reduction The equations are as follows Anodic area e2 CN Au2 CN4 Au2 2 → − − 1 Cathodic area O2 2H2O 2e→H2O2 2OH− 2 The essential of intensification of gold cyanidation

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Gold cyanidation Anfacal

Ball and stick model of the aurocyanide or dicyanoaurate I complex anion Au CN 2 − 4 The chemical reaction for the dissolution of gold the quot Elsner Equation quot follows 4 Au 8 NaCN O2 2 H2O → 4 Na Au CN 2 4 NaOH In this redox process oxygen removes four electrons from the gold simultaneous with

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Optimization Gold Cyanidation Process to Increase Springer Link

Abstract Pongkor Gold Mining has been operated for almost twenty years and produced more than 50 ton of gold One of important process to in gold processing plant at PT Antam Persero Tbk Pongkor Gold Mining Business Unit is CIL Carbon In Leach Process which cyanidation process occur Pongkor has epithermal nbsp

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An improved rate equation for cyanidation of a gold ore

Although cyanide and oxygen are the key reagents in conventional gold cyanidation previous kinetic investigations of gold dissolution from ores have grouped together the free cyanide and dissolved oxygen concentrations into the rate constant of each equation that was proposed It was the main objective of this study to nbsp

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Cyanide Chemistry International Cyanide Management Code ICMI

The reaction known as Elsner 39 s Equation is 4 Au 8 CN O2 2 H2O 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 such as nbsp

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‎ DOC ‎GOLD EXTRACTION PROCESS USING MERCURY

Question 6 Write the balanced equation of the formation of complexe Au CN 4 – 2 Cyanides use in gold extraction After the ore has been excavated it is ground to a size of less than one millimetre Then it is transported to the tanks of the leaching plant This powder is fed into large mechanically stirred tanks where a nbsp

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Molecular weight of Gold I Cyanide Convert Units

Calculate the molar mass of Gold I Cyanide in grams per mole or search for a chemical formula or substance

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Cyanide volatilisation from gold leaching operations and InfoMine

Eq 3 1 Habashi 1970 This reaction forms the basis of the cyanidation process However according to Lorősch 2001 gold dissolution typically consumes less than 1 of the cyanide added during gold leaching and is therefore technically only a side reaction This can be attributed to University of Pretoria etd – Lötter nbsp

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Cyanide Leaching Chemistry amp Gold Cyanidation 911 Metallurgist

17 Mar 2017 Cyanide Leaching Chemistry In a relatively simple system of this type the gold dissolves readily The only requirements are that the gold be free and clean that the cyanide solution contain no impurities that might inhibit the reaction and that an adequate supply of oxygen be present in the solution nbsp

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Optimizing the Cyanide Leaching of Gold Proceedings of the Royal

23 Dec 2015 A second order equation was proposed and developed for the relationship between the gold recoveries and influential factors Gold cyanidation follows an electrochemical–chemical reaction between cyanide and gold at the particle surface and throughout the particle porous volume 12 Math nbsp

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Gold Mining in Waihi New Zealand Institute of Chemistry

carbon Most of the impurities are left behind in the solution Step 3 Gold is stripped off the carbon by mixing it with NaCN and NaOH at 110 o C forming a new solution of cyanide and gold The gold is then converted back to elemental gold in the following electrolysis reactions At the anode 4OH → O2

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Cyanide Leaching Of Gold

Leaching Gold With Cyanide Since the 1890 39 s cyanide has been used to recover gold from gold bearing ores And today over 115 years later most of the worlds gold is recovered with cyanide playing a large part in the beneficiation of the yellow precious metal Chemically it is a rather simple reaction 4 Au 8 NaCN nbsp

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‎ DOC ‎Level 3 Chemistry internal assessment resource NCEA on TKI

identifies describes and gives an account of the chemical processes involved in the extraction of gold using cyanide gives chemical equations for the reactions occurring in the cyanide extraction of gold gives chemical equations for reactions used in reducing the environmental effects of the extraction processes

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The Extraction of Silver Chemistry LibreTexts

26 Jan 2014 Extraction of Silver by cyanide process and its uses Silver also occurs both in combined state as well as in free state The important ores of silver are Argentite Ag2S Copper silver glance Horn silver Ruby silver The silver ores are found along with gold ores in some parts of India

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Use of ferricyanide for gold and silver cyanidation

that cyanide and oxygen act as complex ligand and oxidant respectively and they both play important roles in the gold silver cyanidation process The well known Elsner equation 1946 describes the stoichiometry of the reactions as follows 1 4Ag 8CN− O2 2H2O 2 Ag CN 4 4OH− 1 4Au 8CN− O2 2H2O

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pH ORP Cyanide Leaching Process Understanding Leaching of

A gold cyanide complex will form as the gold dissolves from the rock or pulp finely ground ore according to the equation 4Au 8CN 2H2O O2 → 4Au CN 2 4OH The control of pH in a cyanide leach solution is critical both from a safety and cost viewpoint The process adds cyanide to solution in the form of sodium nbsp

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Selective Mercury Sequestration from a Silver Mercury Cyanide

RANGE FOR REACTION IN CYANIDE LEACH SOLUTION WHERE MERCURY SELENATE PRECIPITATES BUT DOES NOT EDS QUANTITATIVE ANALYSIS OF SILVER SULFIDE PARTICLE REACTED WITH MERCURY CYANIDE Ammoniacal thiosulfate can also leach gold ore Equation 1 where cyanide is nbsp

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Serial Hybrid Modelling for a Gold Cyanidation Leaching Plant

22 Jul 2015 equations of gold and cyanide as well as two kernel partial least square KPLS models which are used as the estimators of the unknown kinetic reaction rates the proposed estimation strategy based on Tikhonov regularization is used to estimate the kinetic reaction rates which can mitigate the effect of

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What is the role of cyanide in mining MiningFacts org

Cyanide is the general term for chemicals which contain a cyano group triple bonded carbon and nitrogen with the chemical formula CN that occur naturally or are 3 The process used to extract gold using cyanide was developed in Scotland in 1887 and was first used in large scale commercial mining by the New nbsp

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COMPARISON OF CYANIDE AND THIOSULPHATE Doria

In alkaline thiosulphate solution where oxygen is as an oxidant the complex redox reaction is shown in Eq 11 11 The thiosulphate leaching of gold in the presence of oxygen needs a suitable catalyst because otherwise leaching is very slow A very efficient catalyst is copper II which is used with ammonia that nbsp

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Extracting Gold HowStuffWorks

Leaching dissolves the gold out of the ore using a chemical solvent The most common solvent is cyanide which must be combined with oxygen in a process known as carbon in pulp As the cyanide and oxygen react chemically gold in the pulp dissolves When workers introduce small carbon grains to the tank the gold nbsp

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Recovery of Gold and Silver and Removal of Copper Zinc and Lead

9 Feb 2015 of gold and silver Cyanidation has been used for over 100 years to extract precious metals from sulfide ores Despite this fact the reactions involved are not fully understood More gold If k is not concentration dependent and the area is unhanging Equation 5 may be integrated resulting in the integrated nbsp

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