Subsequent Gold Research Articles

A Fiber optics based surface enhanced Raman spectroscopy sensor for chemical and biological sensing

This paper investigates an innovative surface-enhanced Raman scattering (SERS) sensor developed on a side-polished multimode optical fiber core. The optical fiber was integrated into specifically designed 3-dimensional printed mold, where manual polishing of the fiber took place. Microsphere Photolithography (MPL) techniques was employed to pattern periodic nanoantenna arrays on the polished surface, incorporating multiple disk diameters at a fixed periodicity. Subsequent gold deposition/lift-off were carried out to transfer the pattern from the photoresist to the fiber core, resulting in highly periodic hexagonal closed pack (HCP) arrays of nanodisks. These arrays can significantly enhance the SERS signal intensity compared to that of the fiber tip. The sensor's performance was demonstrated using various concentrations of Rhodamine 6G (R6G) dye ranging from 10−5 to 10−9 M as a function of disk diameter and sensing surface area. The resulting spectra revealed characteristic peak positions that aligned well with the fingerprint Raman spectra of R6G. The results demonstrates that the sensitivity is 10−9 M for the sensor with an 800 nm disk diameter.

Enantioselective Synthesis of α-Quaternary Isochromanes by Oxidative Aminocatalysis and Gold Catalysis.

A novel strategy that combines oxidative aminocatalysis and gold catalysis allows the preparation of chiral α-quaternary isochromanes, a motif that is prevalent in natural products and synthetic bioactive compounds. In the first step, α-branched aldehydes and propargylic alcohols are transformed into α-quaternary ethers with excellent optical purities (>90 % ee) via oxidative umpolung with DDQ and an amino acid-derived primary amine catalyst. Subsequent gold(I)-catalyzed intramolecular hydroarylation affords the isochromane products with retention of the quaternary stereocenter. A second approach explores the use of allylic alcohols as reaction partners for the oxidative coupling to furnish α-quaternary ethers with generally lower enantiopurities. Stereoretentive cyclization to isochromane products is achieved via intramolecular Friedel-Crafts type alkylation with allylic acetates as a reactive handle. A number of synthetic elaborations and a biological study on these α-quaternary isochromanes highlight the potential applicability of the presented method.

Технология переработки сухих отходов сорбции и растворов хлоридов сурьмы

Reducing the loss of valuable components during the processing of complex gold-antimony ores, increasing the extraction of antimony during the flotation of sulfide minerals, is an urgent scientific problem. The aim of the study is to maximize the extraction of gold and antimony from dry sorption waste after gold cyanidation, and to improve the reagent regime of the antimony mineral flotation process. Research objectives are as follows: evaluation of the technology efficiency for processing dry sorption waste; extraction of gold from the cake of acidic leaching of antimony; production of various antimony-containing products from solutions of antimony chlorides; study of the possibility of replacing lead with a mixture of zinc and copper cations to hydrophobize the surface of antimony sulfide minerals during flotation. The object of the research is man-made and natural mineral raw materials containing gold and antimony. The following research methodology and methods are used: information analysis, evaluation of existing scientific developments, methods of theoretical and experimental research. A new technological solution has been proposed: acidic (a mixture of hydrochloric acid and hydrogen hydroxide) hydrometallurgical technology for processing dry sorption waste in order to extract gold and antimony. Acid treatment makes it possible to completely transfer antimony into solution, significantly improves the quality of the cake for subsequent cyanidation and gold extraction, reduces the volume of material for processing by cyanidation, and simplifies cyanidation technology. Sb2S3 activation and the possibility of lead (Pb(NO3) replacement have been studied 2) a mixture of zinc and copper (ZnSO4 and CuSO4) during the flotation of antimony ores from the Khipkoshinsky deposit in the Transbaikal Region. This has made it possible to create favorable conditions for interaction with xanthogenate and hydrophobize the surface of sulfide minerals. Theoretically, hydrogen sulfide substitutes such as NaCNS, KCNS, CuCNS for use in the flotation process were evaluated.

Safe Havens, Machine Learning, and the Sources of Geopolitical Risk: A Forecasting Analysis Using Over a Century of Data

We use monthly data covering a century-long sample period (1915–2021) to study whether geopolitical risk helps to forecast subsequent gold volatility. We account not only for geopolitical threats and acts, but also for 39 country-specific sources of geopolitical risk. The response of subsequent volatility is heterogeneous across countries and nonlinear. We find that accounting for geopolitical risk at the country level improves forecast accuracy, especially when we use random forests to estimate our forecasting models. As an extension, we report empirical evidence on the predictive value of the country-level sources of geopolitical risk for two other candidate safe-haven assets, oil and silver, over the sample periods 1900–2021 and 1915–2021, respectively. Our results have important implications for the portfolio and risk-management decisions of investors who seek a safe haven in times of heightened geopolitical tensions.

A Pretreatment of Refractory Gold Ores Containing Sulfide Minerals to Improve Gold Leaching by Ammonium Thiosulfate: A Model Experiment Using Gold Powder and Arsenic-Bearing Sulfide Minerals

The use of thiosulfate to extract gold from refractory ores is promising because of its non-toxicity and high selectivity. Sulfide minerals (i.e., pyrite, arsenopyrite, chalcopyrite), major gold carriers in refractory gold ores, however, hinder gold extraction due to the high consumption of a lixiviant. In this study, a new method to improve gold extraction from sulfide bearing gold ores is proposed based on the model experiments using a mixture of gold powder and arsenopyrite-bearing sulfide (HAsBS) ore. The effects of HAsBS ore on gold leaching in ammonium thiosulfate solutions were investigated, and it was found that gold extraction in the presence of HAsBS ore was suppressed because of the unwanted decomposition of thiosulfate on the surface of sulfide minerals. To improve gold extraction in the presence of the sulfide minerals, this study investigated the effects of the pretreatment of HAsBS ore using ammonium solutions containing cupric ions and confirmed that HAsBS ore was oxidized in the pretreatment and its surface was covered by the oxidation products. As a result, thiosulfate consumption was minimized in the subsequent gold leaching step using ammonium thiosulfate, resulting in an improvement in gold extraction from 10% to 79%.

Capacitive Enhancements of the Chiroptical Response in Plasmonic Helicoids

AbstractChiral plasmonics has been actively pursued since pushing its light‐matter interaction to an unnaturally extreme regime. Recently, chirality‐encoded metal–insulator–metal (MIM) motifs have promised compelling advantages in advancing chiroptic responses, as they enable a capacitive coupling and its resultant strong electric and magnetic resonances. However, the deterministic control over chiral MIM working at the visible regime is out of reach. Here, large‐area MIM resonators are demonstrated using non‐lithographically assembled chiral gold nanoparticles (helicoids) and subsequent gold layer deposition, and their boosted chiroptical responses at the visible regime are proven. The thickness of the topcoat Au and the dielectric gap can precisely tune the strength of capacitive coupling. The numerical analyses support that the optimally tuned capacitive coupling in the chiral MIM structure not only strengthens both electric and magnetic dipolar resonances but also makes their spectral positions closer to each other.

Sensitivity of Gold Lixiviants for Metal Impurities in Leaching of RAM Printed Circuit Boards

The importance of gold recovery from waste printed circuit boards is continuously increasing due to raising gold prices and demand as well as the need for innovative and flexible recycling methods for this complex waste stream. The state-of-the-art recycling process aims at the pyrometallurgical recovery of noble metals, mainly using a copper collector. Different technical limitations justify the application of a hydrometallurgical process alternative for recovering gold. The direct application of gold lixiviants on comminuted PCBs is hardly possible due to the high concentration of metal impurities. As a solution, most researchers propose hydrometallurgical separation of disturbing base metals prior to gold extraction. For this, different leaching systems with aggressive chemicals can be applied, often leaving residual base metal concentrations behind. Within this study, two different leaching parameter sets were investigated to separate base metals and determine the impact of residual base metals on subsequent gold recovery. The gold lixiviants that were applied for comparison were thiosulfate, thiourea, iodine-iodide, NBS, and cyanide. It was found that thiosulfate and thiourea are less sensitive than other lixiviants to metal impurities. When base metals are separated completely, gold recovery is strongly improved, and cyanide also achieves a good gold recovery.

Development of Novel Methodologies for Functionalization of Isoxazoles

Isoxazole is a five-membered heteroaromatic ring that is a highly important framework with widespread applications in pharmaceuticals and agrochemicals. Indeed, the isoxazole ring has desirable pharmacological activity because its two contiguous electronegative heteroatoms (nitrogen and oxygen atoms) contribute to hydrogen bonding with various target enzymes and receptors inaccessible by other ring systems. This unique and significant utility has led to great interest in the synthesis of functionalized isoxazoles, and various synthetic approaches have been developed for this class of compounds. Current synthetic approaches are classified into following four groups: (a) 1,3-dipolar cycloaddition, (b) condensation, (c) cycloisomerization, and (d) direct functionalization. Despite the recent much effort on synthetic researches, however, direct functionalization of isoxazoles (approach d) has still been immature to produce a variety of multifunctionalized isoxazoles. We herein describe our recent studies on direct functionalization of isoxazoles based on the generation of 4-isoxazolyl anion species and the subsequent gold (I)-catalyzed electrophilic aromatic substitution type reactions and rhodium (III)-catalyzed carboxylate-directed C-H activation. These developed functionalization methodologies enabled access to novel isoxazole derivatives that are not readily synthesized by other means. In addition, our interest in photolysis of isoxazoles led us to find photochemical conversion of isoxazoles into 5-hydroxyimidazolines.

Optically tunable metal-dielectric diffractive structures

Hybrid metal-polymer micropillar arrays are elaborated by solvent-assisted embossing techniques and subsequent gold deposition. The polymer is poly(methyl methacrylate) (PMMA) grafted with Disperse Red 1 (DR1) azobenzene derivatives. This photochromic material exhibits spectacular photomechanical properties. Under off-normal $p$-polarized illumination in the absorption band of the DR1, the metal-polymer hybrid micropillars bend in a direction determined by the light polarization. The deformation remains stable when the light excitation is turned off. The optically driven modification of the pillar shape allows us to tune the optical properties of the pillar arrays. Very large intensity changes are measured in the diffraction spectra at zero order (specular reflection), first order, and second order, with almost on and off switching of the diffraction efficiency. The photoinduced bending of the micropillars can be fully reversed by switching the linear light polarization to the orthogonal $s$-polarization state. This allows us to restore the initial optical properties of the pillar array. The polarization-controlled reversibility of the pillar deformation suggests a complex photoinduced deformation mechanism involving stress and stress release assisted by the change in the viscoelastic properties of the polymer under illumination in the absorption band of the DR1 chromophore.

Development of an Immunochromatographic Test Based on Rhoptry Protein 14 for Serological Detection of Toxoplasma gondii Infection in Swine

Simple SummaryToxoplasmosis is one of the most common parasitic zoonoses in the world. It not only threatens human health and safety but also causes considerable losses to the global animal husbandry industry. Swine, as an intermediate host of Toxoplasma gondii, has important economic and public health significance, and the global prevalence of T. gondii in swine varies between 10% and 60%. Therefore, it is important to establish simple, effective, sensitive and specific diagnostic methods for the detection and prevention of T. gondii infection in swine. In the present study, we developed a colloidal gold immunochromatographic strip based on rTgROP14, recombinant protein A and monoclonal antibody TgROP14-5D5 for serological detection of T. gondii in swine populations. This new ICT achieved good specificity and sensitivity and has potential for routine serological detection of T. gondii in swine.Toxoplasma gondii, a worldwide distributed apicomplexan protozoan, can infect almost all warm-blooded animals and may cause toxoplasmosis. In order to provide a point-of-care detection method for T. gondii infection, an immunochromatographic test (ICT) was established. The proposed test uses recombinant T. gondii rhoptry protein 14 (ROP14) conjugated with 20 nm gold particles, recombinant protein A as the detection line and monoclonal antibody TgROP14-5D5 as the control line. The specificity, sensitivity, positive predictive value, negative predictive value and stability of this new ICT were evaluated. rTgROP14 was specifically recognized by positive serum of T. gondii but not negative serum. mAb TgROP14-5D5 showed higher specific recognition of T. gondii antigens and was therefore selected for subsequent colloidal gold strip construction. The new ICT based on TgROP14 exhibited good diagnostic performance with high specificity (86.9%) and sensitivity (90.9%) using IHA as a “reference standard”. Among 436 field porcine sera, ICT and IHA detected 134 (30.7%) and 99 (22.7%) positive samples, respectively. The relative agreement was 87.8%. These data indicate that this new ICT based on TgROP14 is a suitable candidate for routine testing of T. gondii in the field.

Development of a surface plasmon resonance sensor using an optical fiber prepared by electroless displacement gold plating and its application to immunoassay.

A simple and low-cost method of fabricating an optical fiber for a surface plasmon resonance (SPR) sensor was proposed. The method is based on the electroless nickel plating and subsequent displacement gold plating of the core of the optical fiber. The thickness of the nickel and gold thin films deposited on the core of the optical fiber could be controlled by measuring the reflected light intensity from the tip of the optical fiber during the plating processes. The sensitivity and resolution of the SPR sensor with the fabricated optical fiber in the refractive index range from 1.333 to 1.348 were 1324.3 nm/RIU and 7.6×10-4 RIU, respectively. The developed SPR sensor was successfully used in the determination of immunoglobulin A (IgA) in human saliva. The IgA quantification results obtained by the SPR sensor were in excellent agreement with those obtained by conventional enzyme-linked immunosorbent assay using a 96-well microtiter plate.

Ultrasensitive Leaky Surface Acoustic Wave Immunosensor for Real-Time Detection of Alpha-Fetoprotein in Biological Fluids

We propose an ultrasensitive leaky surface acoustic wave (LSAW) immunosensor based on molybdenum disulfide @ cuprous oxide—gold (MoS2@Cu2O-Au) nanoparticles and subsequent gold staining for the detection of alpha-fetoprotein (AFP). MoS2@Cu2O-Au nanoparticles, with their large specific surface area and good biocompatibility, not only capture the secondary antibodies (Ab2) but also amplify the mass loading effect of the acoustic wave sensor in the detection of AFP. The immunosensor signals are further amplified upon injection of gold staining solution. The developed immunosensor achieved a low detection limit of 5.5 and 25.0 pg/mL with and without gold staining, respectively. The immunosensor demonstrated its efficiency for the quantitative detection of AFP in complex biological fluids, including human serum and saliva samples, with excellent selectivity and long-term stability, showing great potential for the quantification of AFP in clinical diagnosis.

Mechanism of gold and palladium adsorption on thermoacidophilic red alga Galdieria sulphuraria

Biosorption is a promising alternative to conventional methods for metal recovery during recycling. An extremophilic microalga Galdieria sulphuraria is suitable for use as a biosorbent with the potential for mass production and naturally high and selective adsorption capacity for gold and palladium without modification or extensive pre-treatment. However, the atomic-level understanding of how the biosorbent collects the precious metals was not known. In this study, adsorption mechanisms for G. sulphuraria-derived biosorbent in highly acidic solvents commonly found in metal wastewater were elucidated. It was indicated that the primary site of gold and palladium adsorption was the nitrogen atom on the biosorbent surface in a chlorine-rich environment where enough chlorine atoms were available for the precious metals to form chloride anionic complexes. By using several acidic solvents exhibiting different adsorption efficiency it was found that the more reduced the gold was, the higher the adsorption efficiency. Progressive gold reduction from trivalent to monovalent, then to zerovalent, which consequently produces nanoparticles with metallic gold, contributes to improved adsorption capacity by changing binding partners on the cell surface in the process, vacating adsorption positions for subsequent ionic gold. Redox reactions, including sulphur oxidation were also suggested to promote sustainable reduction of gold while palladium was shown to remain as divalent cations.

Effect of Initial Cell Concentration on Bio-Oxidation of Pyrite before Gold Cyanidation

Bio-oxidation of refractory sulfidic gold minerals has been applied at the commercial scale as a pre-treatment to improve gold yields and reduce chemical consumption during gold cyanidation. In this study, the effect of initial cell concentration on the oxidation of pyritic gold ore was evaluated with four aerated bioreactors at 30 °C with 10% pulp density and pH maintained at 1.4 with NaOH. Results of NaOH consumption and changes in soluble Fe and S concentrations indicated that increasing the initial cell concentration from 2.3 × 107 to 2.3 × 1010 cells mL−1 enhanced pyrite oxidation during the first week. However, by day 18 the reactor with the lowest initial cell concentration showed profound performance enhancement based on soluble Fe and S concentrations, sulfide-S and pyrite contents in the residues, and subsequent gold leaching of the bio-oxidation residues by cyanidation. Overall, the results showed that the cell concentration was clearly beneficial during the initial stages of oxidation (first 7–8 days).

An environmentally friendly method for efficient atmospheric oxidation of pyrrhotite in arsenopyrite/pyrite calcine

Pyrite and arsenopyrite are the most common hosts for invisible gold, but pyrite and arsenic are refractory during conventional sulfide oxidation, which significantly challenges subsequent gold extraction. One option is high-temperature pretreatment of arsenical materials to sequester > 90% of the arsenic as a gas, then convert it to a stable form. This process produces a calcine similar in composition to pyrrhotite (Fe1-xS) but with higher porosity. In this study, the calcine product is oxidized with an efficient, cost-effective atmospheric process using acidic and near-neutral solutions. A sulfur mass balance analysis method based on iron sulfide thermal transformation in nitrogen atmosphere was developed to quantify the oxidation efficiency of pyrrhotite leaching. The optimization confirmed that > 90% of the calcine was oxidized by Fe3+ (5 and 10 g/L) and O2 (0.5 L/min) at pH 1 after 48 h and at 95 °C even without ultrafine grinding. Elemental sulfur was the main oxidation product when the oxidation pH was 1,2. This study provides the foundation for the development of a low-cost and environmentally friendly process option for pretreatment of arsenical sulfide refractory gold materials.

Arsenic removal strategy in the processing of an arsenopyritic refractory gold ore

In the gold mining industry, the exploitation of low-grade refractory deposits generates effluents with high arsenic concentrations. In this study, an additional stage in the processing of an arsenopyritic refractory gold ore was studied. Arsenic extraction in an alkaline pretreatment was evaluated to avoid metalloid release in the subsequent gold thiosulfate leaching stage, without affecting precious metal extraction. Experiments were conducted with different extracting agents (citric acid, sodium bicarbonate, oxalic acid, deionized water); contact time in the alkaline pretreatment stage (6 and 13 days) was also assessed; furthermore, the effect of arsenic extraction time (4 h, 6 days and 12 days), concentration of oxalic acid (0.02, 0.1, 0.5 M) and temperature (25, 70 °C), was studied. The results showed that it is possible to remove arsenic without altering the subsequent release of gold (80%). The best conditions were: 0.1 M oxalic acid for 1 h and at 70 °C. Finally, it was observed that the concentration of As released into the subsequent thiosulfate leach decreases by 97.7% (from 640 to 15 mg/l), thereby conserving its ability to eventually be recycled after gold recovery.

Au/TiN nanostructure materials for energy storage applications

The quest for combining different materials for energy storage has gained key interest in the globe. In this study, titanium nitride (TiN) were synthesized by nitriding of TiO2 followed by subsequent gold (Au) nanoparticles doping using conventional deposition precipitation technique. X-ray diffraction results confirmed the purity of the TiN and Au structural phase. The existence of Au, Ti and N were confirmed using energy dispersive X-ray in each composition. The field emission scanning electron microscopy demonstrated the morphology of TiN in granular shaped nanoparticles and the presence of Au particles. The microstructural analysis was performed using high-resolution transmission electron microscopy and the results show a well-defined (111) crystal plane. Electrochemical properties were examined by cyclic voltammetry, galvanostatic charge–discharge curves and electrochemical impedance spectroscopy. The electrode with 5% Au/TiN shows a specific capacitance of 787 F g−1 at a scan rate of 5 mV s−1 that is far higher compared to 202 F g−1 for the pure TiN electrode. The higher value of capacitance of 5% Au/TiN electrode is attributed due to the conductive and mechanical stable behaviour of both gold and titanium nitride. Hence, the high performing 5% Au/TiN composition can be considered as a favourable electrode material for supercapacitor application.

TiO2 nanorod arrays decorated with Au nanoparticles as sensitive and recyclable SERS substrates

Surface enhanced Raman scattering (SERS) platforms with recyclability are highly required for the practical applications. In this work, TiO2 nanorod arrays decorated with Au particles (Au@TiO2 NRAs) are prepared by glancing angle deposition technology and subsequent gold sputtering. Au@TiO2 NRAs are demonstrated as sensitive SERS substrate while the optimal substrate with high reproducibility and stability is obtained. Illustrated by Frequency-domain finite element method (FEM), this excellent SERS performance can be attributed to the formation of high intensity hot spots located on the gap between Au nanoparticles. Moreover, the SERS substrates are extensively recyclable due to the well-known ability of TiO2 photocatalytic degradation of dye molecule under ultra-violet light.

IDIOPATHIC DIFFUSE PULMONARY OSSIFICATION: A RARE CAUSE OF CALCIFIED PULMONARY NODULES

SESSION TITLE: Medical Student/Resident Diffuse Lung Disease SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Idiopathic diffuse pulmonary ossification is an extremely rare disease that often presents incidentally on chest imaging. While the initial course can often be indolent, the disease course can be severe, and in some cases, fatal. Here, we describe a case of a 21-year-old female who was incidentally diagnosed with diffuse pulmonary ossification. CASE PRESENTATION: The patient underwent tuberculin skin test for school clearance and was noted to have induration to 16 mm with subsequent negative QuantiFERON gold testing. Chest radiograph showed diffuse bilateral peribronchial thickening and nodular interstitial abnormality. The patient reported mild progressive dyspnea on exertion and intermittent dry cough. Her vital signs were unremarkable including an oxygen saturation of 97% on room air. On exam, her lungs were clear to auscultation. Initial computed tomography (CT) scan of the chest showed extensive bilateral centrilobular and peribronchvascular nodules with varying levels of calcification (image 1). Repeat CT scan at 3 months showed no change. Laboratory investigations including calcium, phosphate, sputum acid-fast bacilli, fungal serologies, and rheumatologic screen were normal. Spirometry showed an isolated mild reduction in the DLCO. Bronchoscopy with transbronchial cryobiopsy of the RLL showed pulmonary parenchyma with focal ossification without granulomas, malignancy or amyloid. Cultures were negative. DISCUSSION: Diffuse pulmonary ossification involves the formation of mature bone in the lung and occurs in two forms: nodular and dendriform, both of which can have idiopathic and secondary forms [1, 2]. Ossification typically presents in older men, though has been reported in women or younger adults. Commonly, patients present with absent to minimal symptoms of dyspnea and radiographic findings are out of proportion to symptoms. Spirometry testing is often initially normal but can develop a restrictive pattern with decreased DCLO in later stages. Chest imaging findings include bilateral diffuse calcified micronodules or dense ground glass opacities, with predilection for the lower lobes. Pathology typically reveals ossification and calcification within the alveoli. In later stages, alveolar septal thickening and interstitial fibrosis may develop. Diagnosis can often be made on imaging findings alone, though it can be confirmed with bronchoscopic or surgical biopsy if diagnosis is uncertain. Therapies target lowering serum calcium levels, though no treatments have been shown to affect the progression of disease. For patients with a more aggressive course, lung transplant may be considered [3]. CONCLUSIONS: Pulmonary ossification is a rare, often asymptomatic disorder, that should be suspected in patients with characteristic imaging findings. Early identification can help to monitor progression, though no clear disease modifying therapies have been identified. Reference #1: 1.Tseung J, Duflou J. Diffuse pulmonary ossification: an uncommon incidental autopsy finding. Pathology 38: 45-48, 2006. Reference #2: 2. Reddy TL, von der Thüsen J, Walsh SL. Idiopathic dendriform pulmonary ossification. J Thorac Imaging 27: W108-W110, 2012. Reference #3: 3. Matsuo H. et al, Progressive Restrictive Ventilatory Impairment in Idiopathic Diffuse Pulmonary Ossification Intern Med. 2018 Jun 1; 57(11): 1631–1636 DISCLOSURES: No relevant relationships by Jessica Channick, source=Web Response My spouse/partner as a Consultant relationship with Actelion Please note: $20001 - $100000 Added 04/20/2020 by Colleen Channick, source=Web Response, value=Consulting fee My spouse/partner as a Consultant relationship with Bayer Please note: $5001 - $20000 Added 04/20/2020 by Colleen Channick, source=Web Response, value=Consulting fee No relevant relationships by Tamas Dolinay, source=Web Response

Исследования по переработке измельченного золотомедного флотоконцентрата методом сернокислотного атмосферного окисления

The study is focused on the conditions of sulphuric acid atmospheric oxidation of crushed gold-copper flotation concentrate for obtaining a solid gold-containing product suitable for gold extraction by cyanidation. Additionally, the scope of the study includes the problem of maximising the transfer of copper into a sulphate solution for subsequent separation into a commercial product. The object of research consisted of a gold-copper concentrate with the main copper minerals represented by chalcopyrite and tennantite. Experiments on atmospheric oxidation of flotation concentrate were carried out in a laboratory reactor at a temperature of 90-95°C in a sulphuric acid medium using industrial oxygen and air as an oxidiser. In order to analyse the chemical composition of solutions, atomic absorption, inductively-coupled plasma atomic emission and titrimetric analysis methods were used. The composition of solid phases was studied by assay-gravimetric, assay-atomic absorption and chemical methods. In the course of research on the selection of optimal parameters for conditioning the flotation concentrate prior to cyanidation, the particle size of the material was revealed to be at least 80% of the class, i.e. -20 μm. This contributes to an increase in the subsequent gold cyanidation recovery by 56.0% and a decrease in reagent consumption by 21.0 kg/t (compared to direct cyanidation without pre-treatments). In order to reduce the oxygen consumption in the process of atmospheric oxidation, as well as to increase the extraction of copper, a three-stage scheme of the process was proposed including air bubbling for 8 h, oxygen oxidation for 2 h and air oxidation for 8 h. In this case, the extraction of copper and gold (with subsequent cyanidation) into solution comprised 90.1 and 95.4%, respectively, with the consumption of NaCN decreased to 8.1 kg/t. Atmospheric oxidation of gold-copper flotation concentrate pre-crushed to a particle size of 20 μm in a sulphuric medium by bubbling the pulp with oxygen and air results in high recovery rates for copper into a sulphate solution and gold during cyanidation of solid product following atmospheric oxidation with simultaneous decrease in cyanide consumption.