thiosulfate leaching of silver gold and bismuth from a

Thiosulfate leaching of gold—A review | Semantic Scholar

Abstract The ammoniacal thiosulfate leaching process for gold and silver extraction has been reviewed in terms of leaching mechanism, thermodynamics, thiosulfate stability, and gold recovery options. The application to different ore types and process options have also been discussed. The thiosulfate leaching process it catalysed by copper and has several advantages over the conventional ...

Thiosulfate leaching of silver, gold and bismuth from a ...

Thiosulfate leaching represents an alternative for the non-cyanide leaching of gold, silver as well as for selective leaching of bismuth from complex sulfide concentrates (Hiskey and Atluri, 1988, Marsden and House, 1994, Wan and Brierley, 1997, Ficeriová et al., 2002).

Selective leaching of bismuth from mechanically activated ...

The intensification of the thiosulfate leaching of silver, gold and bismuth from sulfide concentrates using mechanical activation and mechanochemical pretreatment step was investigated.

thiosulfate leaching - Gold Refining Forum.com

May 19, 2011· Has anyone here actually used thiosulfate for leaching gold ore,and had positive results,that can be repeatable as a real leaching process? Has anyone found a real working precipitation process to recover the gold,that works well,and is dependable? Also getting the gold out of the precipitates seems to be a real pain.

silver in galena - Gold Refining Forum.com

Mar 19, 2010· Geonorts: The sodium thiosulfate solution can be prepared with 200 gr of soldium thiosulfate and 800 ml of tap water,you can find sodium thiosulfate as waste in newspapers and hospitals Copper sulfate acts like a catalyst which forms a rare salt of silver,copper and sodium thiosulfate,the silver in this salt could be recover adding some zinc powder and a 5% solution of …

The Extraction of Gold from E-waste by Hydrometallurgy ...

In this research, the waste obtained from the leaching of copper and silver, which contains 0.973 percent of gold, and a mixture of choleric acid, nitric acid were leached with ratios of 1:1, 3:1, 5:1, and 7:1 at 60, 80, and 100 degrees Celsius in 1, 1.5, and 2 hours time in 20 g per liter concentration at the mixing speed of 800 rounds per minute.

sodium thiosulfate gold extraction

gold extraction process by thiosulfate rkblawcollege.in. Read "Gold extraction from thiosulfate solution using ... · recovered powders from a sodium thiosulfate leach of gold plated pins. if all my ... Inquire Now; Gold cyanidation Wikipedia

1. Introduction

Another method is thiosulfate leaching that has been analyzed by Muir and Aylmore [18], Jeffrey et al. [33], Feng and Deventer [34] . The disadvantage of this process is oxidation of thiosulfate and turn into polythionats that will increase the consumption of reagent. Thiourea leaching is done in acidic medium.

CMC Chimie - Gold WITHOUT cyanide - YouTube

Aug 18, 2015· Eco-friendly Gold and Silver Processing Technology Using Ammonium Thiosulfate Leaching - Pilot station presentation.

thiosulfate gold leaching 」

In thiosulfate gold leaching, Cu2+ ions are commonly used as oxidizing agents, while the thiosulfate ion acts as a ligand forming a soluble gold thiosulfateammonia complex Aylmore and Muir, 2001. It was suggested that gold leaching in the absence of Cu2+ ions, with …

Thiosulfate leaching of gold—A review - ScienceDirect

Thiosulfate leaching can be considered a non-toxic process, the gold dissolution rates can be faster than conventional cyanidation and, due to the decreased interference of foreign cations, high gold recoveries can be obtained from the thiosulfate leaching of complex and carbonaceous-type ores. In addition, thiosulfate can be cheaper than cyanide.

COMPARISON OF CYANIDE AND THIOSULPHATE LEACHING …

leach significant quantities of gold without consuming excessive quantities of reagents. Thiosulphate is a more effective lixiviant of preg-robbing and high-copper ores than cyanide because ammoniacal thiosulphate leaching is less sensitive than cyanidation to

Silver dissolution in a novel leaching system: Reaction ...

This type of leaching is a better leaching procedure for recovery of gold and silver from PCB waste than the classical toxic cyanide leaching. 84 % Cu, 82 % Fe, 77 % Al, 76 % Zn, 70 % Ni, 90 % Pd ...

process for thiourea and thiosulphate leaching - Gold ...

Nov 09, 2015· I expect Iron content will have a profound effect on a thiosulfate leach. When thiosulfate is used for dissolving silver chloride encrusted karat gold, it is then cemented with steel wool. I would assume nothing will go into solution until all the iron is gone.

Gold extraction - Wikipedia

If the gold can not be concentrated for smelting, then it is leached by an aqueous solution: . The cyanide process is the industry standard.; Thiosulfate leaching has been proven to be effective on ores with high soluble copper values or ores which experience preg-robbing: the absorption by carbonaceous components which preferentially absorbs gold and gold-cyanide complexes.

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Gold recovery from ammonia-thiosulfate leaching solution ...

1. Introduction 1.1. Chemistry of thiosulfate leaching of gold. Since the 1880's, Cyanidation has been the main method for the extraction of gold and silver from a wide range of ores, because of its high extraction efficiency and cost/benefit ratio.

(PDF) Leaching of Gold and Silver from Anode Slime with ...

Leaching experiments of anode slime were performed with several inorganic acids (HCl, HNO_3 and H_2SO_4) together with thiourea and thiosulfate solution to recover gold and silver.

THIOUREA LEACHING OF GOLD AND SILVER - TECHNOLOGY …

T1 - THIOUREA LEACHING OF GOLD AND SILVER - TECHNOLOGY UPDATE AND ADDITIONAL APPLICATIONS. AU - Hiskey, J. B. PY - 1984/12/1. Y1 - 1984/12/1. N2 - The review of recent literature relating to the use of thiourea as a lixiviant for gold and silver indicates only …

THIOSULPHATE LEACHING – AN ALTERNATIVE TO …

alternative to cyanidation for some gold bearing ore bodies. Whether the leaching is performed in stirred tank reactors or heaps, the size and type of equipment needed for a thiosulphate leaching flowsheet is very similar to a conventional cyanide leach. SGS is a global technical leader in the field of thiosulphate leaching, and our

Leach Gold using Hyposulphite Of Sodium AKA Thiosulfate ...

Thiosulfate Gold Extraction The fact that gold will dissolve in sodium hyposulphite solutions is known from the lixiviation of silver and gold ores. The gold will dissolve only in small quantities. According to researchers, if gold leaf is treated for a time with sodium hyposulphite solutions

Thiosulphate Leaching | Mining | SGS

Thiosulfate leaching offers a number of benefits related to gold recovery yields and environmental concerns: Thiosulfate leaching of gold ores has great potential to reduce the impact on the environment. Unlike cyanide, which is highly toxic, the chemicals used in the thiosulfate leaching process are benign.

THIOSULFATE LEACHING OF SILVER FROM A SOLID …

respectively. It confirms the possibility of thiosulfate leaching application for silver extraction. The effect of Cu(II) ions addition on silver leaching from solid residue after pressure leaching was investigated at thiosulfate and ammonia concentrations of 0.5 and 0.6 mol/dm 3, respectively. The concentration of Cu(II) was 0.1 mol/dm .

Kinetic Investigation and Dissolution Behavior of Cyanide ...

May 10, 2019· Thiosulfate as most promising cyanide alternative lixiviant was not capable to dissolve pure or silver-alloyed gold samples. The thiosulfate leaching experiments caused the formation of a …

US4778519A - Recovery of precious metals from a thiourea ...

A method is provided for recovering gold and silver from precious metal bearing materials including ores, leaching residues, flue dust, electronic scrap, jewelry scrap, etc. In the method, the gold and silver are extracted from the precious metal bearing materials with a thiourea solution to form a thiourea leach, and the thiourea leach is contacted with carbon to adsorb the gold and silver ...

(PDF) A Review of Thiosulfate Leaching of Gold: Focus on ...

A Review of Thiosulfate Leaching of Gold: Focus on Thiosulfate Consumption and Gold Recovery from Pregnant Solution Article (PDF Available) in Metals - Open Access Metallurgy Journal 7(6):222 ...

Effect of Silver in Thiosulfate Leaching of Gold–Silver ...

One promising alternative to cyanide for the leaching of gold is thiosulfate due to its low toxicity and efficiency in leaching gold from low-grade and carbonaceous ores and concentrates. Much of the published research focuses to optimizing the reagent concentrations to develop a suitable process for industrial applications. However, there are few studies on the effect of silver content on ...

CN104911366A - Method for recovering valuable metals from ...

The invention provides a new fully-hydrometallurgical method for recovering valuable metals from silver-bismuth slag through using aqua regia and sulfuric acid to avoid defects of present silver-bismuth slag processing technologies. All metal elements except silver and lead in the silver-bismuth slag can be rapidly dissolved by using the strong acidity of aqua regia and sulfuric acid, Au, Bi ...

Kinetic Investigation and Dissolution Behavior of Cyanide ...

Thiosulfate as most promising cyanide alternative lixiviant was not capable to dissolve pure or silver-alloyed gold samples. The thiosulfate leaching experiments caused the formation of a stable passive layer after 2–3 hours, which led to a mass increase (0.3 M thiosulfate …

Thiosulfate leaching of silver, gold and bismuth from a ...

The intensification of the thiosulfate leaching of silver, gold and bismuth from sulfide concentrates using mechanical activation and mechanochemical pretreatment step was investigated. The physico-chemical changes in a complex sulfide concentrate (Casapalca, Peru) as a consequence of mechanochemical pretreatment had a pronounced influence on ...

Sodium thiosulfate for small-scale gold leaching from ...

I recently read that sodium thiosulfate can be used for gold and silver leaching in much the same way as cyanide, but with no worries about toxicity. This intrigues me: aqua regia is a pain to work with, and cyanide is too toxic for an amateur, but thiosulfate is already one of my favorite reagents - cheap, nontoxic, and has so many uses.

Sodium Thiosulphate Gold Leaching

The gold industry has been seeking alternative reagents for leaching gold from low-grade ores for the past 25 years. The cost and transport of cyanide, the poor recovery of gold from carbonaceous ores, the lack of selectivity of cyanide towards copper minerals and the cost of waste treatment are real factors which can make cyanide unattractive in some circumstances. However there are also ...

Optimizing the thiosulfate leaching of gold from printed ...

The gold leaching process followed the pseudo-second order kinetic model at the low concentration range of the reactants such as 40–60 mM thiosulfate, 5–7 mM copper(II) and 0.22–0.247 M ammonia, and the pseudo-first order kinetic model at the mid concentration range (60–70 mM thiosulfate, 7–9 mM copper(II) and 0.247–0.263 M ammonia).

Improvement of thiosulfate stability in gold leaching ...

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 (NH4)2S2O3, 0.03M CuSO4 and 3M NH3 at pH 10.2 for 24 hours. In the testing, thiosulfate consumption was 30 kg/t of ore.

The Leaching of Gold in Cyanide Solutions in the Presence ...

A fundamental electrochemical study of gold and gold/silver alloys in thiosulfate solutions showed that although the oxidation is a complex process, there was no selective dissolution of either ...