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US4559209A Leaching refractory gold ores Google

A method is disclosed for leaching a gold ore which is refractory due to the presence of sulphide minerals of arsenic and antimony. The ground ore is leached with cyanide in a pipe reactor at a pressure of between 5 and 8 MPa. The terminal pH value of the pulp is controlled to be 10 or less than 10.

The Leachox™ Refractory Gold Process The Testing, Design

Leachox, Ultra fine grinding, Vasilkovskoye, Refractory, Imhoflot pneumatic flotation, Leaching, Oxidation . ABSTRACT . The Leachox refractory gold process has to date been applied to the selectivetreatment of several refractory gold ores but on a

Oxidative leaching of refractory sulphidic gold tailings

Sep 01, 2020 The gold extraction from the refractory sulphidic gold tailing by [Bmim + HSO 4− ]-water solution 20% (v/v)/thiourea/ferric ion was conducted at longer extraction times of 1 day, 2 days, 3 days and 5 days at pH = 1, temperature 60 °C and shaking speed of 250 rpm. Fig. 3 demonstrates the gold extraction at longer leaching times.

Leaching refractory gold ores Gold Metallurgy

Apr 02, 2016 In general, refractory gold ores may be treated in a number of ways and over the past few years, 5 approaches have been taken, all with varying degrees of success depending on the ore. As shown, pressure leaching gives high gold recoveries from a variety of ore types, whilst direct leaching variable poor recoveries.

Pore Evolution in Refractory Gold Ore Formed by Oxidation

Jan 20, 2022 Refractory gold ore is usually affected by the associated carbonaceous matter through the preg-robbing effect, which is eliminated by oxidation roasting, followed by leaching, to achieve a satisfactory gold leaching efficiency. Roasting–leaching experiments, pore structure measurements, scanning electron microscopy (SEM), and X-ray diffraction are used to explore

Gold Leaching from a Refractory Gold Concentrate by the

In this research, NaCl — NaClO solution is used to leaching gold from a refractory gold concentrate, and the influence of NaCl and NaClO concentration, reaction time to the leaching rate were investigated in this experiment. The raw materials and the leaching residue were characterized by a series of analysis methods such as XRD, XRF, SEM and

Improvement of Gold Leaching from a Refractory Gold

May 16, 2017 The total gold leaching ratio of a refractory As-, S- and C-bearing gold concentrate calcine by direct cyanidation was only 70.2%, but there was a significant variation in the gold leaching ratio based on size fraction, in the following order: medium size fraction (82.6%) > coarse size fraction (72.3%) > fine size fraction (59.7%).

Improving the gold leaching process of refractory ores

Apr 01, 2019 A reactor to improve the leaching kinetics of refractory gold ores.. • The Jetleach reactor is designed to propagate micro-cavitation in a chamber filled with oxygen. • This reactor can improve the gold recovery while decreasing the leaching time. • The Jetleach is a potential solution to the cyanidation problems of refractory ores.

US20130091990A1 Method for recovering precious

The present disclosure is directed to a process for recovering a precious metal from a pregnant leach solution using a resin extractant. The precious metal is eluted from the loaded resin using an eluant comprising trithionate. The barren resin is contacted with a sulfide, bisulfide, and/or polysulfide to convert sorbed trithionate to thiosulfate.

i need an alternative gold processing system for sulfide ores

Designing gold extraction processes: Performance study of a Nine attributes: Ore type, Gold ore grade, Gold distribution, Gold grain size, Sulfide present, Arsenic sulfide, Copper sulfide, Iron sulfide and Clay present were modelled and several literature sources of actual gold mines and processes were used for acquiring cases for the system.

Gold Leaching from a Refractory Gold Concentrate by the

In this research, NaCl — NaClO solution is used to leaching gold from a refractory gold concentrate, and the influence of NaCl and NaClO concentration, reaction time to the leaching rate were investigated in this experiment. The raw materials and the leaching residue were characterized by a series of analysis methods such as XRD, XRF, SEM and

(PDF) APPLICATION OF DIAGNOSTIC LEACHING

diagnostic leaching was performed on refractory gold ore containing 5.9% pyrrhotite, 0.9% pyrite, 1.3%. arsenopyrite and bulk concentrates generat ed from the flot ation tests. Results showed that

Improvement of Gold Leaching from a Refractory Gold

A total gold extraction of 70.2% could only be reached via direct cyanidation from a refractory As-, S- and C-bearing gold concentrate calcine, and the gold extraction varied noticeably with different size fractions. The reasons for unsatisfactory gold extraction from the calcine were studied through analyses of chemical composition, chemical phase and SEM-EDS of different

Biooxidation-thiosulfate leaching of refractory gold

Aug 15, 2020 A process of biooxidation followed by thiosulfate leaching of gold from refractory gold concentrate was investigated. Mineralogical studies on the concentrate showed that very fine gold grains (<10 µm) were encapsulated in pyrite and arsenopyrite, while the proportion of monomer gold was only 21%. The gold-bearing sample was identified as a high-sulfur fine

Recovery of Gold from the Refractory Gold Concentrate

Apr 28, 2020 Microwave technology has been confirmed to be suitable for use in a wide range of mineral leaching processes. Compared to conventional leaching, microwave-assisted leaching has significant advantages. It is a proven process, because of its short processing time and reduced energy. The purpose of this study was to enhance the gold content in a refractory

The Metallurgy of Cyanide Gold Leaching An Introduction

Oct 20, 2014 Leaching gold with a cyanide solution remains the most widely used hydrometallurgical process for the extraction of gold from ores and concentrates. Despite the difficulties and hazards of working with cyanide, no other process has yet been proven to be an economic viable alternative. Refractory Ores/Solid-Solution Gold: In some ores, Au

(PDF) Ammoniacal thiosulphate leaching of gold ore

The European Journal of Mineral Processing and Environmental Protection Vol.3, No.3, 1303-0868, 2003, pp. 344-352 Ammoniacal thiosulphate leaching of gold ore R.K. Rath, N. Hiroyoshi, M. Tsunekawa*, T. Hirajima Laboratory of Mineral Processing and Resources Recycling, Graduate School of Engineering, Hokkaido University, Sapporo, 060-8628, Japan Received 30

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.

Establishing thE ProcEss MinEralogy of gold orEs

refractory gold can only be achieved by employing a pre-oxidation process prior to cyanide leaching. Antimony, bismuth sulfide and telluride gold ores: Antimony, bismuth sulfide and telluride gold ores are often somewhat refractory due to the presence of slow-dissolving gold minerals such as aurostibite, maldonite and gold tellurides

US5536297A Gold recovery from refractory carbonaceous

A process for recovering gold in which an ore slurry of refractory sulfidic and refractory carbonaceous ore having preg-robbing characteristics due to the presence of organic carbon is subjected to pressure oxidation in an autoclave. The oxidized ore slurry is mixed with a thiosulfate salt lixiviant, which mixture is maintained at a pH between 7 and 8.7 while the slurry is agitated

Supercritical Water Treatment of Refractory Gold Ores

Nov 06, 2017 With pretreatment, gold recovery was 90%; by contrast, gold recovery was below 10% without pretreatment. Recent work at the Bureau of Mines showed some unique and potentially useful results when refractory gold ores were pretreated with supercritical water before standard leaching. This work is described below.

Gold processing 101 Mining Magazine

Sep 07, 2017 In the case of Goldstrike, this was a double-refractory ore combining sulphide-occluded gold with preg-robbing carbonaceous material that rendered the ore unsuitable for conventional cyanide leaching and carbon adsorption.

Specific Refractory Gold Flotation and Bio-Oxidation

enhanced the gold leaching rate and yield. This work reflect the remarkable impact of subtle deposit feature changes on extraction performance. Keywords: refractory gold ores; ore mineralogy; secondary minerals; rheology and leaching kinetics; mechano-chemical activation 1.

releaching og gold samples thetipsypizza

leach because of non-effective leaching of sulphide and silica bearing samples containing gold. The advantage of MIBK method is primarily associated with its cheaper cost, than the Fire Assay fluxes. As exploration samples require a better detection limit than that offered by gravimetric procedures, Fire

US5536297A Gold recovery from refractory carbonaceous

A process for recovering gold in which an ore slurry of refractory sulfidic and refractory carbonaceous ore having preg-robbing characteristics due to the presence of organic carbon is subjected to pressure oxidation in an autoclave. The oxidized ore slurry is mixed with a thiosulfate salt lixiviant, which mixture is maintained at a pH between 7 and 8.7 while the slurry is agitated

Recovery of gold from the refractory gold concentrate

The leaching efficiencies of metal ions (As, Cu, Zn, Fe, and Pb) and recovery of gold from refractory gold concentrate were investigated via nitric acid leaching followed by microwave treatment. As the acid concentration increased, metal ion leaching increased. In the refractory gold concentrate leaching experiments, nitric acid leaching at

Improved thiourea leaching of gold with additives from

Non-cyanide gold leaching serves as a promising green approach for eliminating cyanide utilization and the resulting environmental pollution from cyanide use. In this work, thiourea leaching combined with mechanical activation was employed to extract gold from a refractory gold concentrate calcine.

Specific Refractory Gold Flotation and Bio-Oxidation

enhanced the gold leaching rate and yield. This work reflect the remarkable impact of subtle deposit feature changes on extraction performance. Keywords: refractory gold ores; ore mineralogy; secondary minerals; rheology and leaching kinetics; mechano-chemical activation 1.

Complete process and equipment solutions for refractory

Sep 17, 2021 The current high gold price is increasing the focus on the development of refractory gold ores and concentrates. TON Outotec can deliver the three main oxidative processes for the treatment of refractory gold concentrates BIOX, pressure oxidation, and roasting and also supply equipment for ultra-fine grinding as a fourth, non

The Metallurgy of Cyanide Gold Leaching An Introduction

Oct 20, 2014 Leaching gold with a cyanide solution remains the most widely used hydrometallurgical process for the extraction of gold from ores and concentrates. Despite the difficulties and hazards of working with cyanide, no other process has yet been proven to be an economic viable alternative. Refractory Ores/Solid-Solution Gold: In some ores, Au

Minerals Free Full-Text Specific Refractory Gold

Jan 19, 2021 Despite numerous reported studies on improved gold extraction (by cyanide leaching) from complex low grade ores [9,10,11,12,13,14,15,16], there is still a lack of fundamental knowledge and understanding on the interplay between refractory ore-specific primary and secondary mineral phases, solution chemistry, and the particle-solution

Roasting temperature effect on the recovery of refractory

The amenability of a refractory ore to the extraction of gold and silver by cyanide leaching was investigated. Diagnostic leaching tests were also performed to shed light on the refractory

(PDF) Ammoniacal thiosulphate leaching of gold ore

The European Journal of Mineral Processing and Environmental Protection Vol.3, No.3, 1303-0868, 2003, pp. 344-352 Ammoniacal thiosulphate leaching of gold ore R.K. Rath, N. Hiroyoshi, M. Tsunekawa*, T. Hirajima Laboratory of Mineral Processing and Resources Recycling, Graduate School of Engineering, Hokkaido University, Sapporo, 060-8628, Japan Received 30

Processing technologies for gold-telluride ores

Abstract: Gold telluride ores are important gold refractory ores due to the presence of sulfides and other gangue materials. The classification and main physical properties of gold telluride ores were described, and possible treatment methods including flotation, leaching, and

A novel method for the recovery of silver from

In this study, leaching of gold from the refractory Kaletaş ore (in which gold/silver alloy is the only mode of occurrence detected) in ammoniacal thiosulfate solutions was studied. A two-level

Cyanide Leaching Chemistry & Gold Cyanidation

Feb 06, 2015 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 throughout the reaction period.

FLOWSHEET DEVELOPMENT FOR GOLD OREBODIES

process are gold leach efficiency and cyanide consumption as a function of the fineness of grind and other leach conditions. REFRACTORY GOLD ORE PROCESSES ‘Refractoriness’ results in poor gold recovery by standard processing techniques, and can be due to either chemical or physical interference. An example of chemical interference is the

(PDF) Gold Extraction and Recovery Processes For Internal

The lower sensitivity to base metals (As, Pb, Cu, Sb, Zn) or impurities render possible the use of this process on many refractory gold ores. Thiourea leaching has been tried on different materials and ores with success. Pre-roasted materials were leached with gold extractions up to 99 per cent with leaching time as short as 30 minutes.