Copper-gold Ore Research Articles

Quantifying pyrrhotite superstructures in copper-gold ore flotation through synchrotron X-ray diffraction analysis

Pyrrhotite, a significant sulfide mineral in base metal sulfide deposits, exists in various superstructures including magnetic (4C) and non-magnetic (5C and 6C) types. Identifying and quantifying pyrrhotite superstructures in an ore sample has been a challenge, hindering efforts to improve pyrrhotite rejection in copper–gold flotation. This study employed synchrotron X-ray powder diffraction (S-XRPD) analysis to quantify pyrrhotite superstructures in the concentrates obtained from flotation of a copper–gold ore after grinding with forged steel and 30% chromium grinding media. S-XRPD demonstrated a superior capability in detecting characteristic peaks of 4C, 5C and 6C pyrrhotite superstructures compared to conventional XRPD. Utilizing the Rietveld refinement method, the identified pyrrhotite superstructures were quantified. These findings were successfully validated through independent X-ray fluorescence analysis on elemental compositions. The quantification work demonstrated that 30% chromium grinding media enhanced the floatability of all pyrrhotite superstructures over forged steel grinding media and each pyrrhotite superstructure in the copper–gold ore resembled a copper sulfide mineral rather than pyrite in response to grinding media during flotation. This research highlights the potential of S-XRPD as an effective technique for identifying and quantifying pyrrhotite superstructures in ore samples and determining their flotation behaviors.

Simultaneous Determination of Ultra-Trace Pt, Pd, Rh, and Ir in Gold Mining Residue by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) with an Antimony-Copper Fire Assay and Microwave Digestion

The evaluation of the flow direction of platinum group elements (PGEs) during gold-copper ore mining is challenging due to the uneven distribution and low content. Therefore, it is vital to accurately and simultaneously determine ultra-trace PGEs Pt, Pd, Rh, and Ir in gold mining residue samples. In this study, a method to simultaneously determine ultra-trace Pt, Pd, Rh, and Ir in gold mining residue is reported using Sb–Cu fire assay, microwave digestion, and inductively coupled plasma-mass spectrometry (ICP-MS). The Sb–Cu fire assay was used to enrich Pt, Pd, Rh, and Ir, obtaining Sb–Cu alloy particles that concentrate these elements. An optimal microwave method was employed to digest the Sb–Cu alloy particles. In ICP-MS, the collision reaction interface was used to eliminate the interferences of other elements and improve the accuracy. Moreover, the matrix-matched multi-external standards combined with internal standard calibration were utilized to reduce the error. High concentrations of Au, Ag, and Pb showed no interferences with Pt, Pd, Rh, or Ir determination. The limits of detection for Pt, Pd, Rh, and Ir were 0.018, 0.052, 0.064, 0.035 ng·g−1, respectively, and the relative standard deviation was 5.18, 4.66, 1.55, and 3.17%. Additionally, the determination of Pt, Pd, Rh, and Ir in standard reference materials showed good agreement with the certified values. In summary, a reliable and efficient method is provided to determine various PGEs which is of great significance for gold-copper ore mining.

FLOT-ART: An integrated plant optimization tool for the flotation of copper and copper–gold ores

Conventional flotation plant optimization procedures for copper and copper–gold ores have served the industry well over decades. But with the present trend in declining ore grades along with increase in metallurgical complexity, many flotation operations are experiencing significant challenges in sustaining design or operational budgeted recovery and concentrate quality targets. The need to use non-conventional water sources like brackish, sea water, and recycled process water has exacerbated the problem. Also with the emergence of various large mechanical cells and new non-mechanical flotation technologies, the ongoing use of traditional plant operational strategies is further adding to the challenges.This paper discusses an integrated plant optimization tool for the flotation of complex copper and copper–gold ores in addressing the present challenges, branded as FLOT-ART (Flotation Advanced Recovery Technology). This includes a cohesive flotation plant optimization approach starting with a mineral surface preparation step in grinding followed by advanced mineral-specific electrochemistry and cell hydrodynamics based circuit operation. This approach then allows an ore-specific grade-recovery control strategy for optimum flotation performance. This development is based on extensive greenfield projects, brownfield plant expansion studies along with operational optimization programs involving bench and plant campaigns. Principles of the FLOT-ART optimization system will be presented in this paper along with some commercial applications in the flotation of copper and copper–gold ores.

Unveiling different pyrrhotite superstructures in copper-gold ore samples: Insights from advanced spectroscopic and microscopic characterization

Pyrrhotite exhibits diverse non-stoichiometric superstructures with varied surface reactivities, causing contradictory flotation behaviors in industrial processes. The challenges in managing pyrrhotite in processing plants stem from the lack of systematic mineralogical techniques to distinguish its superstructures in low-grade ore samples without any preprocessing, such as purification or manual sample picking. This study established a comprehensive technique to differentiate between pyrrhotite superstructures in low-grade metal sulfide ores using spectroscopic and microscopic methods. The examined samples came from a natural copper–gold orebody from Western Australia and the flotation concentrate of the ore. Initial identification of pyrrhotite through XRD confirmed the presence of pyrrhotite in the samples but failed to discern magnetic and nonmagnetic pyrrhotite superstructures due to the samples' low pyrrhotite content and XRD peak overlaps. In this regard, magnetic colloid technique (MCT) was utilized to effectively identify the presence of both magnetic and nonmagnetic pyrrhotite superstructures in the samples. Energy-dispersive X-ray spectroscopy (EDS) analysis revealed the Fe:S (at.%) ratio ranging from 0.840 to 0.930 for both the ore and the flotation concentrate, affirming the presence of both magnetic and nonmagnetic pyrrhotite with possible 4C, 5C and 6C superstructures. Based on the information obtained from XRD, MCT and EDS, Electron Backscatter Diffraction (EBSD) analysis successfully solved the challenge of identifying pyrrhotite superstructures. By comparing Kikuchi patterns from various zones with different Fe:S ratios to reference patterns, the EBSD confirmed the presence of 4C, 5C and 6C pyrrhotite superstructures in the examined samples. This methodology establishes a comprehensive framework for identifying pyrrhotite superstructures in complex ore samples, offering insights for industrial applications.

Comparative characteristics of efficiency of pneumatic and pneumo-mechanical flotation machines in copper–gold ore processing

Comparative characteristics of efficiency of pneumatic and pneumo-mechanical flotation machines in copper–gold ore processing

Технологические основы переработки скарновых медно-золотосодержащих руд Кыргызской Республики

Introduction. The paper studies the matters of processing of skarn copper-gold ores from a deposit in the Kyrgyz Republic. Materials and methods. As a study task, the authors performed an analysis of the material composition, including micro- and macroscopic types of analyses are presented. Results. Textural-structural analysis and mineralogical characteristics of the main ore minerals is detailed. The characteristic features of the material composition of the studied types of ores are highlighted and described. The reagent suite for processing of skarn ores has been established by means of additional feed of weakly selective depressants (Na2SiO3) and effective flotation reagents to the process, the introduction of which can significantly improve the concentrate quality. The study direction is also supplemented by the consideration and introduction of the process of mechanical activation into the process flow diagram as a reserve in increasing the grade of metals in the concentrate through the mechanical liberation of minerals by ultrafine grinding. The forms of metal loss with concentrating tailings, which are represented by wollastonite, garnet (andradite) and pyroxenes, clay-micaceous minerals, feldspars, and talc are determined. Discussion. The main losses of sulphide copper are associated with the presence of intergrowths of copper minerals with barren minerals in the samples. When evaluating copper minerals in tailings, copper is present in sulphide minerals – 79.2% and 20.8% rel. belongs to the oxide minerals. Conclusion. The paper summarizes the results of the study with the developed closed flotation flowsheet for the processing of copper-gold skarn ores, which makes it possible to obtain the flotation concentrate with grade of Cu – 25.01%, Au – 55.02g/t, Ag – 401g/t, with recovery into concentrate of Cu – 84.65%, Au – 87.94%, Ag – 89.44%. Concentrate output 2.33%. The implementation of the proposed flowsheet will ensure the achievement of planned production performance in the processing of skarn ores. Resume. At the end of the study work, the authors issued recommendations on adjusting the reagent suite with the inclusion of the weakly selective depressant – liquid glass (Na2SiO3), introducing the process of attritioning the feed of the cleaning operation (ultrafine regrinding) and considering the regularity of the phase composition of the copper minerals of skarn ore from the copper grade, providing the initial grade of copper at 0.9-1.0% in the processed ore by blending the ore feed ore to the concentrator. Suggestions for practical application and direction for future research. The materials of the paper can be useful for mining and processing enterprises when processing skarn copper-gold ores.

The Genetic Features and Flotation Properties of Porphyry–Copper–Gold Ore (Malmyzh Deposit, Khabarovsk Krai, Russia)

The Genetic Features and Flotation Properties of Porphyry–Copper–Gold Ore (Malmyzh Deposit, Khabarovsk Krai, Russia)

Evaluation of a novel electrode design for high voltage pulse ore pre-concentration

High Voltage Pulse (HVP) enabled ore preconcentration has the potential to provide large energy savings and upgrade Run-of-Mine ores. The concept is well established in laboratory settings but is yet to be demonstrated at the throughputs needed for industrial uptake of the technology. To scale up this concept from laboratory batch tests to a continuous operation, a novel grizzly-electrode design that integrates pulse discharges for particle breakage and size-based separation into a single step has been patented. In the initial evaluation of the system, two cylindrical electrode bars were adopted with an experiment design to simulate continuous feeding operation. Synthetic particles and a low-grade gold-copper ore were used for the initial evaluation. The evaluation showed pre-concentration can be achieved. Factors affecting the system performance were identified and limitations of the grizzly electrodes are discussed.

Comprehensive Recovery of a High-sulfur Copper-gold Ore in Shandong

The raw gold grade of a mine in Shandong is 1.42 g/t, and it is accompanied by copper and sulfur minerals, and the embedding is closely related, so it is difficult to obtain the ideal index using the original flotation process. In order to realize the effective recovery of gold, copper, and sulfur, the test study of mixing-separation flotation and priority flotation is carried out. The results show that the mineral is more suitable for the beneficiation process of mixing-separation flotation. The recovery rate of gold, copper, and sulfur is 70.42%, 93.58%, and 68.85%, and the recovery rate is 22.89% higher than the priority flotation. The produced copper and gold mixed concentrate and sulfur concentrate can be directly sold to realize the effective recovery of gold, copper, and sulfur.

Study on Epithermal Gold Mineralization System at Shwebontha Prospect, Monywa Copper-Gold Ore Field, Central Myanmar

The Shwebontha prospect area is situated in the Central Volcanic Belt, central Myanmar, where the well-known Sagaing Fault serves as its eastern boundary. This study aims to document key the mineralogy, host rock geochemistry and ore mineralizing fluids. The mineralization, hosted by Upper Oligocene to Middle Miocene rhyolites, displays a strong lithological control. Mineralization is characterized by gold-bearing silicified massive ore and chalcedonic quartz veins in which sulfides are clustered and disseminated not only in quartz gangue but also in rhyolite host rocks. The significant ore minerals in the mineralized veins include pyrite, sphalerite, galena, chalcopyrite, and gold. Common hydrothermal alterations such as silicic, argillic and propylitic alteration types are recognized. According to the fluid inclusion data and interpretation, ore mineralizing fluids in the research area are characterized by formation temperatures of 260-280 °C and salinity of 0.35-2.41 % wt. NaCl eq. respectively. Mixing of hydrothermal fluids was generally considered to be an effective mechanism for ore transport and deposition.

Advanced hydrometallurgical techniques applicable to gold-copper and copper-gold ores. Рractices adopted abroad

Currently, many foreign mining companies process gold ores containing considerable amounts of copper that is soluble in the cyanide process. When this process is used for processing of copper-gold ores, difficulties occur as copper minerals can behave differently when being dissolved. To stop copper cyanides from ending up in tailing dumps, techniques are employed that help break up these compounds. Combined with excessive consumption of cyanide when building compounds with copper, this can entail a significant cost. Hence, of economic and ecological relevance would be the processes that help generate copper as a byproduct of cyanidation while ensuring cyanide recovery. Such processes (they are partially adopted on a commercial scale) include SART/AVR, Activox, CESL, Dynatec, Albion, Biocop, Platsol, Intec, Vitrokele, Hydrocopper, as well as processes based on active carbon and ion exchange adsorption, liquid extraction and so on. This review examines and compares the above processes pointing out their advantages and drawbacks, as well as factors constraining their application. The review also looks at a number of separation techniques to separate copper and gold, copper and cyanide.

Study on Comprehensive Recovery and Utilization of a Low-grade Gold-Copper Ore in Fujian

Study on Comprehensive Recovery and Utilization of a Low-grade Gold-Copper Ore in Fujian

Fluid Inclusion Study of Epithermal Quartz Veins from the Kyaukmyet Prospect, Monywa Copper-Gold Ore Field, Central Myanmar

The Kyaukmyet prospect is located near the main ore bodies of the Kyisintaung and Sabetaung high-sulfidation Cu-Au deposits, Monywa copper-gold ore field, central Myanmar. Lithologic units in the research area are of mainly rhyolite lava, lapilli tuff and silicified sandstone, mudstone and siltstone units of Magyigon Formation which hosted to be polymetallic mineralization. Our field study recorded that epithermal quartz veins are hosted largely in rhyolite lava and lapilli tuff units. Those quartz veins show crustiform, banded (colloform), lattice bladed texture and comb quartz. The main objectives of the present research in which fluid inclusion studies were considered to conduct the nature, characteristics and hydrothermal fluids evolution from the epithermal quartz veins. In this research, there are three main types of fluid inclusions are classified according to their phase relationship (1) two-phase liquid-rich inclusions, (2) the coexisting liquid-rich and vapor-rich inclusions, and (3) only vapor-rich inclusions. Microthermometric measurements of fluid inclusions yielded homogenization temperatures (Th) of 148–282 °C and final ice-melting temperature (Tm) of -0.2°C to -1.4°C . The value of (Tm) are equal to the salinities reaching up 0.35 to 2.07 wt % NaCl equiv. respectively. Estimation formation temperature of the quartz veins provide 190°C and 210°C and paleo-depth of formation are estimated to be between 130m and 210m. Petrography of fluid inclusion and microthermometric data suggest that fluid boiling as well as mixing processes were likely to be happened during the hydrothermal fluid evolution at the Kyaukmyet prospect. According to the characteristics of many parameters including petrography of fluid inclusion, microthermometric data, paleo-depth, evidence of quartz vein textures and types of hydrothermal alteration from the Kyaukmyet prospect allows to interpret these data to be the low-sulfidation epithermal system.

Опыт развития, внедрения и стандартизации BIM (ТИМ)-проектирования в горнодобывающей отрасли

The modern metals industry is characterised by a downward trend in the quality of ores involved in processing, and conventional methods of extracting useful components are inefficient for raw materials with complex composition. To maintain the growing level of metal production it is required to introduce new efficient technologies for processing of low-grade and refractory ores as well as man-made deposits. The article describes processing methods of refractory raw materials with high cyanide content using copper-gold ores as an example, where gold is the primary commodity, and copper is the accompanying useful component. The most common method of processing copper-gold ores is preconcentration followed by selective leaching of copper and gold. In some cases, technologies involving copper by-products and cyanide recovery from the cyanide leaching solutions offer equally effective options for processing of the copper-gold ores and concentrates. Copper-gold ores are processed at gold mines using the cyanide procedures, supplemented if required by gravity and flotation concentration. In all variations of the cyanide treatment, most of copper minerals actively react with cyanides of alkali metals, binding the CN– ions into the copper complex of [Cu(CN3)]2–. This reaction results in an increased solvent consumption, as well as in number of challenges related to cleaning tailings and slurries from highly toxic cyanide compounds and dissolved copper. In addition to technological complications associated with the need to meet strict requirements for the maximum permissible concentrations, copper accumulated in the cycling solutions also causes a decrease in gold extraction from the processed ores.

Kazmekhanobr's technologies in the field of processing of low-grade gold-bearing ores and technogenic raw materials

The Republic of Kazakhstan has been increasing gold production annually for the last 10–15 years. According to the results of 2019, Kazakhstan ranks 13th in the world in terms of gold production (77 tons), in terms of reserves — 16th in the world (377.5 tons). The article presents information about the innovative developments of Kazmekhanobr in the field of processing of poor goldbearing ores and man-made raw materials. Information on implemented technologies and projects in Kazakhstan for recent years is given. Kazmekhanobr’s deve lopments cover the whole complex of technological stages of processing of poor gold-bearing ores and man-made raw materials by heap leaching technology: ore preparation, leaching process, sor ption extraction of gold from productive solutions, desorption of gold from saturated sorbents and electrolytic extraction of gold from rich eluates. In particular, the company for the first time in Kazakhstan in 1998 developed and implemented pre-pelleting of ore and laying it in a pile leaching stack using a stacker at the mines “Suzdal”, “Mukur”, “Mizek”, “Komarovsky”, etc. It was also developed the highly efficient innovative technology of gold heap leaching from poor gold-bearing ores, complex gold-copper ores and technogenic wastes, which is characterized by low consumption of water and reagents and accordingly low negative load on the environment at the mines “Zhanan”, “Mukur”, “Miyali” “Balazhal”, “Aksu”,“Bestyube”,“Uzboy”, etc. Patents were obtained and a three-stage cascade scheme of sorption extraction of gold by ion exchange resin, original design of sorption columns and binding of columns were introduced, which allowed to maximize the heap leaching process and increase its efficiency, minimize processes of resin pumping processes and, accordingly, the mechanical impact on them, will increase saturation of the resin with gold and reduce the turnover of gold with working solutions at the Zhaltyrbulak, Uzboy, Vasilyevskoye deposits. Innovative processes of highefficiency technology of gold desorption and ion exchange resin regeneration, electrolytic extraction of gold from commodity regenerates have been introduced, in which the duration of gold desorption and resin regeneration together with gold electrolysis does not exceed 18–24 h. According to the projects developed by Kazmekhanobr with the use of innovative technologies, plants for the production of Dore alloy in Ust-Kamenogorsk, Semey and Stepnogorsk, Makmala (Kyrgyzstan) and the Asi gold mining plant (China) were built and successfully operate.

Petrography, mineralogy, litho-geochemistry and fluid inclusion gold-copper deposit Gheshlaghe Mil, northwest of Saveh

The Gheshlaghe mil deposit is located in the Urumieh-Dokhtar magmatic belt. Vein- type mineralization is concordance within the rhyodacitic and rhyolite meta-tuff with Eocene age. Alteration zones of sericite, silica, argillic and iron oxides are observed in the investigated area. Primary sulfide minerals of pyrite, fine-grained chalcopyrite and Oxidized specularite and Secondary minerals goethite, limonite, malachite and quartz in Microscopic and field studies have been identified. Based on X-ray diffraction analysis studies minerals such as chlorite, illite, kaolinite, hematite, quartz, mica group and calcite have been observed in the bearing gold veins. According litho-geochemical studies, the gold element has a positive correlation with iron, molybdenum, nickel and lead. A number of 157 fluid inclusion studies in the Gheshlaghe Mil ore mineralizaion area has been showed mineralization temperature of 99 to 299 ° C, rate of salinity ore deposit 1.81 and 12.30 equivalent to the Nacl weight percent. Using Raman laser studies (13 points), the presence of gaseous phases (CO2, N2, H2O) in the fluid inclusions have been demonstrated. Regarding to studies have been done in this area, the Gheshlaghe Mil ore mineralization can to know to a vein type- hydrothermal bearing gold-copper ore deposit.

The quantification of entropy for multicomponent systems: Application to microwave-assisted comminution

The second law of thermodynamics, through exergy analysis, is commonly applied to quantify process inefficiencies in metallurgical reactors, however, it has not yet been used to understand physical processes and changes in particle-based systems. Correlating the state of mixing of particle texture and homogeneous liquid mixtures is of importance. This paper applies the exergy analysis and excess entropy method to two sets of experiments highlighting the differential breakage as microwave pre-treatment is applied to a gold-copper ore. Grinding kinetic properties were measured following the top-size fraction method and calculated using the population balance model. The approach combines the mixing entropy on the system level (streams) and the entropy for multicomponent particle systems, using automated mineralogy data to quantify the effects of intergrowth and improvements in grinding performance. This is a first step towards understanding mineral processing not only in terms of energy conservation (first law of thermodynamics) but also in terms of the quality of energy available at multicomponent systems (second law of thermodynamics). When applied to comminution processes, this methodology enables us to understand the change in particle composition (its degree of liberation) as well as changes in particle size, being an important measure of process efficiency and selectivity.

CRITERIA AND SEARCH SIGNS FOR ENDOGENOUS MINERALITY IN NORTHERN BUKANTAU

This paper examines the geological structure and patterns of placement of the copper-gold ore occurrence. For the first time, the industrial significance of Cu mineralization in North Bukantau was shown on the example of the Karamurun ore occurrence, which have great promising potential for expanding the raw material base of the Central Kyzyl Kum.

The Santa Lúcia Cu-Au deposit, Carajás Mineral Province, Brazil: a Neoarchean (2.68 Ga) member of the granite-related copper-gold systems of Carajás

The Santa Lúcia copper-gold deposit lies in the southeastern portion of the Carajás Mineral Province, along NW-SE splays of the Carajás Fault. The deposit is hosted by a rhyolitic subvolcanic rock, which is crosscut by pegmatite intrusions. The paragenetic evolution at Santa Lúcia encompasses an early stage of chlorite alteration, followed by potassic alteration with microcline, greisenization (quartz-muscovite-tourmaline), copper-gold ore precipitation, and late sericite and hematite vein formation/fracture infill. Copper mineralization is dominantly represented by chalcopyrite-sphalerite-pyrrhotite-pentlandite-pyrite breccias, which are spatially associated with greisen alteration and characterized by the enrichment of light rare earth elements (LREE), Ni, Co, and Cr. The alteration types, mineralization styles, and ore assemblage suggest that the Santa Lúcia deposit could represent a member of the Paleoproterozoic (ca. 1.88 Ga) granite-related copper-gold systems of Carajás (e.g., the Breves and Estrela deposits). However, the in situ U-Pb analyses of ore-related monazite yield a weighted average 207Pb/206Pb age of 2688 ± 27 Ma, thereby constraining the timing of mineralization at Santa Lúcia to the Neoarchean. Moreover, tourmaline from the pegmatite and within the ore zones has a range of δ11B values from − 3.7 to − 0.6‰, therefore linked to a magmatic boron source. Collectively, these results indicate that the Santa Lúcia deposit is the first reduced magmatic-hydrothermal, iron oxide–poor system formed in the Neoarchean, coeval with the 2.72–2.68 Ga metallogenic event responsible for the genesis of important iron oxide copper-gold (IOCG) deposits in the Carajás Mineral Province.

Technological basis of processing of serpentinite copper-gold ores in the Kyrgyz Republic

Annotation. The article is devoted to the development of an effective technology for processing serpentinite ores from the Bozymchak deposit in the Kyrgyz Republic. Based upon the analysis of mineralogical, physical and chemical parameters of the ore, the authors set reasons for the decrease in technological indicators of the existing concentrator and determine concentrating properties of the reviewed serpentinite resistant material by applying methods of intensifying the flotation process by using additional flotation collectors/depressors and introducing the process of mechanochemical activation of the pulp before flotation. In the proposed technological flowsheet, main requirements for the technological flowsheet and reagent suite of processing serpentinite ores are formed and it is acknowledged that an increase in the grinding size, introduction of the selective copper collector and additional depressor determines the prospects for improving the “reagent” component of determining factors of the set task. Materials of the article can be useful for mining and processing enterprises while involving resistant copper bearing, magnesian serpentinite ores in the processing in order to increase the raw material base of the existing mining and processing complex.