Copper Oxide Ore Research Articles

Compositional peculiarities of the primary, mixed, and oxidized copper ores in gabbroids of the Volkovsky massif (Middle Urals, Russia)

The Ural type magmatic copper deposits in gabbro are assigned to a specific type of copper deposits which exploitation substantially depends on the oxidation degree of the ores, that is often not unambiguous. At the Volkovskoe Cu-Fe-V deposit (Middle Urals, Russia), three technological grades of the copper ores are known, the primary, oxidized, and mixed ones, that are distinguished based on the relative content of Cu2+ in the total copper balance. This paper presents petrological, petrochemical, geochemical, and mineralogical characteristics of natural varieties of the copper ores of the Northwestern zone of the Volkovskoe deposit. It is demonstrated that the criterion for distinguishing the technological grades of the copper ores by the relative Cu2+ content does not reflect the real degree of the supergene oxidation for the selected technological varieties. The results of our research suggest a necessity of studying the copper sulfides in more detail to clarify peculiarities of the redox conditions of the ore formation, to correct the indicators of the primary and supergene copper oxidation degree, which may provide new criteria to determine the boundaries between the technological grades of copper ores, using the Volkovskoe ore deposit as an example.

Fundamentals of copper(II) adsorption on phyllosilicate minerals relevant to crud formation in solvent extraction from heap leach liquors

Because of the common presence of different silicate minerals, like kaolinite, montmorillonite and muscovite as gangue minerals in the beneficiation of copper oxide ores, the interaction between copper(II) ions in solution and each of these minerals is a field of strong interest, considering their implications on the aggregation of these minerals in the extreme pH conditions typical of hydrometallurgical unit operations for copper production. After copper adsorption isotherms determination at pH 2 and 4, specific adsorption data were fitted to both Langmuir and Freundlich models. It was found that adsorption is systematically larger at pH 4, and that montmorillonite is the mineral that displays a larger adsorption capacity, as in principle expected by its larger cation exchange capacity, CEC. A good fitting to the Langmuir model was obtained for the three samples, and montmorillonite also appears to conform to Freundlich isotherm predictions, as the tested concentrations of copper(II) do not allow to reach saturation. Furthermore, some desorption is measured for kaolinite and muscovite at the highest copper concentrations, probably because of significant interactions between the adsorbed ions. No such desorption was detected in montmorillonite samples. An XPS analysis of the surfaces of the three minerals suggests that copper adsorption in kaolinite is not associated to a cation exchange process but rather to electrostatic interactions between silica-like faces of the clay. In contrast, ionic exchange of structural calcium (for montmorillonite) or potassium (in the case of muscovite) seems to be the predominant mechanism of Cu(II) adsorption in the other two samples. Electrophoretic mobility determinations agree with this hypothesis: the mobility (always negative, with no traces of charge inversion) decreases in absolute value when kaolinite particles are in contact with solutions of increasing copper concentration at pH 2 or pH 4. On the other hand, the electrophoretic mobility values of muscovite and montmorillonite showed a weak pH and copper concentration dependence, a result that matches well with the ion exchange processes detected in the XPS measurements.

Leaching Thermodynamics of Low-Grade Copper Oxide Ore from [(NH4)2SO4]-NH3-H2O Solution.

This paper describes a highly alkaline low-grade copper oxide ore. Copper can be selectively leached out while other metals are retained. A thermodynamic model of the CuO-(NH4)2SO4-NH3-H2O system was established for the leaching of tenorite (CuO) under conditions of mass and charge conservation. MATLAB's fitting functions, along with the diff and solve functions, were used to calculate the optimal ammonia concentration and total copper ion concentration of tenorite under different ammonium sulfate concentrations. The effects of various ammonia-ammonium salt solutions (ammonium sulfate, ammonium carbonate, ammonium chloride) on the copper leaching rate were investigated. Results show that under the conditions of an ammonia concentration of 1.2 mol/L, an ammonia-ammonium ratio of 2:1, a liquid-solid ratio of 3:1, a temperature of 25 °C, and a leaching time of 4 h, the copper leaching rate from the ammonium sulfate and ammonium chloride solutions reaches 70%, which is slightly higher than that of ammonium carbonate. Therefore, an ammonia-ammonium sulfate system is selected for leaching low-grade copper oxide due to its lower corrosion to equipment compared to the chlorination system. The impact of this study on industrial applications includes the potential to find more sustainable and cost-effective methods for resource recovery. The industry can reduce its dependence on resources and mitigate its environmental impact. Readers engaged in low-grade oxidized copper research will benefit from this study.

Influence of the Mixture of Xanthates collectors on the Flottation of Difficult Copper Ici de Oré to Float-Case of Minerals Fill 18 Deposit Shangulowe

This paper presents the results of a study conducted to highlight the influence of the mixture of xanthate collectors on the flotation of copper oxide ores. The Shangolowe deposit sample assayed 3.22% copper and 0.08% cobalt, and by means of mineralogy and chemical analysis the gangue appears dolomitic. Test optimization ratio and the main sulfudizing collector were performed, testing after which the dosage rates of 4000g NaSH / dT ore and 400g KAX /dT ore were used as a reference for further testing. Xanthate collectors namely: KAX, KEX, SIBX and SNPX were tested alone and their specific behaviors were reported. The study showed that KAX increase the recovery and three other collectors improved concentrates quality. They were then taken two to two mixed in the proportions of 25% -75% 50% -50% 75% -25%. It appears from these tests that the mix-KAX/SIBX taken in ratios of 75 and 25%, stood out all tests because it offered good selectivity and improved metallurgical performance. Comparative testing of cleaning under standard conditions and the best test mixture, also confirmed an improvement in the selectivity of 7 points compared to the usual KAX. A comparison of the collector’s costs, helped highlight a desired gain per ton contained copper with the use of mixed collectors which was about 13% compared to the use of KAX alone. Operating conditions and flotation scheme on the test which offered the best metallurgical performance subsequently proposed to the operator, who was consolidating the results obtained previously with cyclic tests in laboratory and pilot plant.

Efficient Acid Leaching of Low Carbonate Copper Oxide Ore: A Focus on Impurity Minimization

Efficient Acid Leaching of Low Carbonate Copper Oxide Ore: A Focus on Impurity Minimization

Leaching Kinetics of Cu from Low-Grade Oxidized Copper Ore with High Alkalinity Gangue Using Edta·2na Solution

Leaching Kinetics of Cu from Low-Grade Oxidized Copper Ore with High Alkalinity Gangue Using Edta·2na Solution

Investigation of Leaching Conditions and Leaching Kinetics of Oxidized Copper Ore Malachite at Atmospheric Pressure Using Tartaric Acid Solution

Investigation of Leaching Conditions and Leaching Kinetics of Oxidized Copper Ore Malachite at Atmospheric Pressure Using Tartaric Acid Solution

Iron Oxide-Copper Mineral Associations in Supergene Zones: Insights into Flotation Challenges and Optimization Using Response Surface Methodology.

In this study, batch flotation tests were conducted to investigate the flotation of oxidized copper ore from the supergene zone of the Bounhas deposit. Utilizing the Response Surface Methodology (RSM) anchored on the Box-Behnken Design (BBD), the effects of parameters such as collector dosage, sulfidizing agent, copper oxide and iron oxide grades, and particle size on copper recovery were explored. ANOVA and response surface plots elucidated the complex behavior of copper flotation. Mineralogical analyses of the initial feed and postflotation tails were performed on an industrial scale using advanced Zeiss microscopy. The quadratic model with an R 2 of 94.49% accurately captured the impact of the process parameters on copper recovery. Among the key findings, the sulfidizing agent exhibited the most substantial quadratic effect, while the copper oxide grade had the most substantial linear impact on recovery. A pivotal observation was the link between copper losses in tailings and specific iron oxide-copper associations. Optimization identified conditions leading to a maximum copper recovery rate of 71.49%. When validated industrially, the model demonstrated robust applicability for analogous mineral processing contexts. The study's mineralogical insights enhance our understanding of the supergene zone mineralization and offer a solid foundation for subsequent in-depth mineral processing studies.

Flotation activation mechanism of trithiocyanuric acid to malachite

Malachite is a typical refractory copper oxide mineral. In this paper, trithiocyanuric acid (TMT) was used as a novel activator for the activated flotation of malachite for the first time. The effect of TMT on the flotation behavior of malachite was studied and the activation mechanism was discussed. The flotation test results showed that TMT exhibited superior activation performance over sodium sulfide, achieving a high flotation recovery rate of 97.50 % at TMT 90 mg/L and pH 7. The contact angle confirmed malachite improved from 53.3° to 90.1° after TMT treatment, indicating enhanced hydrophobicity of the mineral surface. FTIR and EDS analyses provided clear evidence of chemical adsorption of TMT tautomers onto the malachite surface. SEM images further illustrated the presence of dense particles formed after TMT treatment. XPS revealed that TMT exhibited a strong adsorption effect on malachite, leading to an increase in copper sites and the formation of highly reactive Cu+. The activation mechanism was elucidated as the reaction between Cu sites on malachite and S and N atoms in TMT, forming Cu-S and Cu–N fractions crucial for activation. The high efficiency and low dosage of TMT make it a promising activator for malachite, offering a novel avenue for the effective recovery of malachite-type copper oxide ore resources.

Study on Process Mineralogy of the Combined Copper Oxide Ore in Tibet and Acid Leaching Behavior with Calcium Fluoride

The Yulong copper deposit in Tibet is a typical porphyry copper deposit, with about 30 million tons of copper oxide ore in the surface layer. However, more than 40% of the copper resources are in a combination state, resulting in an extraction efficiency of only 50% for copper via the hydrometallurgical process. In this study, the process mineralogy of the combined copper oxide ore was systematically investigated and a calcium fluoride-enhanced leaching process is proposed to increase the leaching efficiency of the combined copper ore. The process mineralogy of the combined copper oxide ore was analyzed using various testing techniques, including chemical analysis, X-ray diffraction, and a process mineralogy parameter testing system (Mineral Liberation Analysis). The results revealed that limonite accounted for 86.12% of the sample, and 63.51% of the copper resource existed in the form of combined copper oxide in limonite. However, it is difficult for the uniformly distributed combined copper oxide in limonite to sufficiently make contact with sulfuric acid, which is the leaching agent, resulting in low copper leaching efficiency. The enhanced leaching behavior of the combined copper oxide ores was also investigated, thereby determining effective and economical enhanced leaching conditions. Under optimal conditions, at a grinding fineness ratio of −0.074 mm (accounting for 85%), liquid-solid ratio of 4:1, sulfuric acid concentration of 50 g/L, temperature of 30 °C, CaF2 dosage of 1% of the ore mass, and leaching time of 4 h, the copper leaching efficiency increased to 60.57%, which was 7.34% higher than that of atmospheric pressure leaching. Finally, the enhanced leaching slag was analyzed using an electron probe microanalyzer. It indicated that fluorine ions can erode the combined copper oxide ore and facilitate the diffusion of hydrogen ions inside the limonite, thereby achieving a strengthening effect.

Enhanced leaching of copper from refractory oxidized copper ore by calcium fluoride: Behavior and mechanism

The Luanshya area of Zambia is rich in copper oxide resources. However, copper mainly exists in biotite and phlogopite, which presents challenges for efficient extraction. To improve the leaching rate of copper from these ores, local hydrometallurgical plants use heating and stirring; however, the leaching rate is not high. To address the issue in this work, CaF2 was introduced as a leaching aid, and the effects of various parameters on leaching were systematically studied. The results revealed that when the dosage of CaF2 is 5wt% of raw ore mass, the dosage of sulfuric acid is 120 kg/t, the leaching temperature is 60 °C, and the leaching time is 200 min with a slurry concentration of 30wt%, the leaching rate of copper can reach 80.44%. Compared with regular heating stirring acid leaching, the copper leaching rate was found to increase by 8.76%, while the leaching temperature decreased by 5 °C and the leaching time shortened by 40 min. The results of the HSC Chemistry 6.0 thermodynamic calculations and mechanism analysis indicated that F can promote the fracture of Si–O and Al–O bonds in the crystal structure of biotite and phlogopite in sulfuric acid solution, enabling a direct reaction between the acid and copper. The proposed method can be applied not only to the treatment of cupriferous mica ores but also to the processing of other copper ores. This process is more efficient and cost-effective than the regular heating–stirring acid leaching process.

A metallurgical technology investigation of the Wangxiangping ancient smelting sites at Daye County, Hubei Province

In the spring of 2022, the Beijing University of Science and Technology conducted an archaeometallurgical survey at the Wangxiangping site in Daye County. This exploratory excavation revealed pottery and metal smelting artifacts dating back to the Shang and Zhou dynasties. Charcoal samples from the third stratigraphic layer were carbon-dated to as early as the late Shang Dynasty. The SEM-EDS (Scanning Electron Microscopy-Energy Dispersive Spectroscopy) method was utilized for analyzing metallurgical artifacts across all stratigraphic layers at the site. The findings suggest that both pure copper smelting and tin bronze smelting activities were simultaneously conducted at this location. The analysis indicates that secondary copper oxide ore underwent reduction smelting, leading to the production of pure copper and high-grade matte. Additionally, tin ore was used in bronze production, with tin serving as an alloying element. However, no remnants from casting activities were identified during this survey. The investigation and subsequent analytical processes performed at this site provide substantial evidence supporting further research into copper smelting practices in Daye area during Shang and Zhou dynasties.

Flotation separation mechanism of malachite from calcite using the pentyl xanthate as the collector

Calcite is a commonly associated gangue mineral in oxidized copper ore, while the flotation separation of oxidized copper ore from calcite is a bottleneck technology in the utilization of carbonate-type oxidized copper ore. The present study applied the pentyl xanthate (PX) as a collector to efficiently separate malachite and calcite without any other reagents. The flotation results indicate that the PX dosage is a key factor determining the flotation separation results of malachite and calcite. When its dosage reaches 1000 mg/L, the flotation recovery rate of malachite can reach 88.7 %, while calcite is less than 5 %. The flotation test of real ore contained these two minerals further confirmed that the malachite could be separated from calcite using PX as the collector. The mechanism and characterization analysis show that the selective substitution reaction between xanthate ions and OH ions on the malachite surface could generate hydrophobic substances of copper xanthate, which largely improves the hydrophobicity of the malachite surface. This study is expected to provide theoretical and practical assistance for the efficient flotation beneficiation of low-grade marble-type copper oxide ore.

Utilization of polymeric binders to agglomerate oxidized copper ore

Permeability reduction is a major challenge in heap leaching, primarily caused by the accumulation of fines that move with the leaching agent, leading to the formation of dead zones and channeling within the heap. In the Aria copper beneficiation plant, the 0–2 mm fraction with a copper grade of 1.4% undergoes pre-separation prior to heap loading without further processing. This study investigated the potential of using the agglomeration method to improve permeability in the case of using the 0–2 mm fraction of ore. Mineral compounds, such as sodium silicate and calcium sulfate, and non-ionic, cationic, and anionic polymer compounds, were used in the agglomeration process. The strength of interparticle bonding was evaluated by measuring the fine migration percentage (FMP) in the soak test. The results revealed that agglomerates produced using non-ionic compounds had the highest bonding strength, with an FMP of 3.89%, the lowest of all the compounds tested. This enhanced bonding strength was attributed to the combined influence of hydrogen bonding forces and van der Waals forces.

Interface adsorption mechanism of 5-nonyl salicylaldehyde oxime on malachite surface and its flotation separation performance with calcite and quartz

In this study, 5-nonyl salicylaldoxime (5-NSA) was synthesized and used as a malachite collector. Its flotation performances and adsorption mechanism were systematically investigated by micro-flotation experiments, contact angle measurements, SEM-EDS, FT-IR, XPS and DFTB+ simulations. The micro-flotation test results showed that 5-NSA produced high recovery of malachite at pH 9.0–10.0, while showing lower collecting power to calcite or quartz. The contact angle analysis results indicated that the hydrophobicity of malachite surface was promoted after the adsorption of 5-NSA. SEM confirmed the adsorption of 5-NSA on malachite surface. FT-IR and XPS analysis results confirmed that O and N atoms in the oxime group were immobilized on malachite surface with Cu through OCuO and NCuO bonding. Their adsorption performances on malachite surface were simulated by DFTB+ method, including 5-NSA, tert-butylsalicylaldehyde oxime (TBSA) and salicylaldoxime agents, which analyzed the bond lengths of their covalent bond formation with Cu and speculated their adsorption properties. In general, according to the experimental test and simulation results, 5-NSA showed a stronger power to malachite than TBSA and salicylaldoxime, and only a small dosage can produce a high malachite recovery. The findings of this research will be helpful to improve the comprehensive utilization efficiency of malachite and promote the metallurgy of copper oxide ores.

Developing of a Counter-Current Copper Leaching Process Using Response Surface Methodology

ABSTRACT Due to the scarcity of water in many parts of the world, wastewater generated by hydrometallurgical processes has been recognized as a valuable resource for recovery or reuse. A method for reusing hydrometallurgical raffinate in the leaching of low-grade oxide copper ore in a counter-current leaching process was evaluated. In the first stage of the investigation, the influential factors on copper leaching, such as the amount of acid consumed (200–400 g/kg of ore), the initial iron concentration of the raffinate (5–25 g/L), the liquid-to-solid ratio (2–10 mL/g), and the duration of the leaching process (15–75 min), were examined using response surface methodology coupled with central composite design. Two responses, copper recovery and final copper concentration, were selected to determine the optimal conditions for the leaching process. Based on the statistical model, it was found that using 325 g/kg of ore of consumed acid, an initial iron concentration of 10 g/L, a liquid-to-solid ratio of 4 mL/g, and a leaching time of 60 min would result in higher values for both responses. Confirmation runs were conducted to validate the selected conditions and the suitability of the statistical model. Additionally, compositional and morphological characterization of samples before and after the leaching process was conducted using field diffusion scanning electron microscopy and X-ray diffraction analysis, which showed the dissolution of compounds such as tenorite and cuprite. In the second stage, a two-unit counter-current leaching system was adopted, as hydrometallurgical processes are usually carried out in multiple stages on an industrial scale. This leaching system was designed to maximize copper dissolution by considering the information obtained from the response surface methodology. The use of this leaching system increased the overall leaching efficiency by up to 80%. By characterizing the solid samples, it was found that the copper extraction percentage in a counter-current leaching system could be increased by simultaneously precipitating iron-bearing compounds.

Flocculation Behavior of Ultrafine Silica Particles in Acid Leaching Pulp by Nonionic Polymeric Flocculants

Sedimentation of ultrafine silica particles that exist in acid leaching pulp and their separation from Pregnant Leach Solution largely determines the efficiency of a hydrometallurgical process utilizing copper oxide ore. Thickener on a larger scale can allow longer sedimentation, generating low overflow turbidity but high economic input. In this paper, the flocculation behavior of quartz particles in sulfuric acid solution using nonionic flocculants polyethylene oxide (PEO) and polyacrylamide (PAM), as well as ionic cofactor montmorillonite (MMT) and nonionic cofactor tannic acid (TA), were investigated, with the dynamic size of flocs and counts of fines being monitored using an in situ particle size measurement technique, namely the focused beam reflectance measurement (FBRM), under turbulent conditions. Attention was paid to variables affecting quartz flocculation properties from both physicochemical and hydrodynamic aspects such as shear intensity. The flocculation mechanism was investigated using zeta potential and dynamic light scattering measurements. It was found that the TA promotes the bridging flocculation of PEO-quartz by forming associative complexes with larger clusters in solution, while MMT electrostatically adsorbs on the quartz surface, enhancing its bridging with PAM. Low turbidity benefited from the higher shear resistance of the compact flocs structure provided by PEO/PEO + TA/PAM + MMT. Efficient solid–liquid separation was achieved by using the synergistic flocculation of small molecule cofactors and polymer flocculants.

Contribution of ammonia in xanthates adsorption onto copper oxide mineral surface in high-alkaline solution

Ammonia is a useful modifier for enhancing surface sulfurization in copper oxide ore flotation using xanthate as a collector. However, its potential role in the reaction of sulfhydryl collector with sulfurized copper oxide mineral in a complex pulp has been neglected. This work investigates the contribution of ammonia to xanthate adsorption on the sulfurized malachite surface, independent of its effect on sulfurization. Zeta potential measurements indicate that NH3·H2O increases the surface potential of malachite and enhances the proximity of xanthate to the malachite surface in a strong-alkaline solution. Adsorption tests and time-of-flight secondary ion mass spectrometry analysis demonstrate that NH3·H2O can increase the xanthate adsorption density. Spectroscopic analysis reveals copper(I) xanthate and dixanthogen as the primary xanthate products, with their quantities increasing upon NH3·H2O treatment. Thermodynamic analysis of the reaction of malachite, HS−, and xanthate to form copper(I) xanthate and dixanthogen shows that NH3·H2O treatment enhances the stability of the reaction compared to its absence. Thus, NH3·H2O treatment increased the recovery of sulfurized malachite by over 10%. This study offers a comprehensive understanding of ammonia modification for enhancing sulfurization–xanthate flotation of copper oxide minerals and provides a scientific basis for developing high-efficiency collectors.

Thermodynamic Calculations of Direct Reduction Smelting Technology of Copper Oxide Ores Based on Smelting Slag from the Yubeidi Site, Yunnan Province

The current research on metallurgical remains from scientific excavations in northeast Yunnan from the Bronze Age period is insufficient. In order to study the smelting technology of the Bronze Age in north-eastern Yunnan, samples of slag and mineral excavated from the Yubei Di site in Dongchuan were examined. Based on the outcome of the characterization analysis, a simulation was executed utilizing the software Factsage 7.1 in order to generate a phase diagram that accurately portrays the melting procedure. This simulation aimed to produce the most credible representation of the phase transition by employing computational methods. Characterisation methods included Metallographic Microscopy, Scanning Electron Microscopy Energy Dispersive Spectromicropy (SEM-EDS), X-ray diffraction (XRD), and Radiocarbon Date (14C dating). The results showed that there was much copper ore left in the slag of the site. Most of these copper ores were in the form of copper ferrite or cuprous oxide. The copper ore was copper oxide ore, and metal copper particles appeared in a small amount of the slag. Most of the slags unearthed from the site of the Yubeidi site were products of sulfur-containing oxide reduction and smelting into copper. Based on the outcomes of the simulations, it was established that the slag excavated from the Yubeidi site was mainly from the reduction and smelting process of sulphur-containing copper oxide minerals into copper, without consciously adding fluxes, not having mastered the slag-making techniques for different types of copper ores, and with primitive techniques. The carbon 14 dating results show that the age of the slag was during the Spring and Autumn Period and the Warring States Period.

Using a Modified Reagent in the Enrichment of Oxidized Copper Ores

The problem of processing oxidized copper ores is acute in the copper industry of Kazakhstan. The solution to the problem of dressing oxidized ores is seen in changing the properties of oxidized minerals towards hydrophobization of the surface, which would increase the efficiency of the flotation method of dressing. Existing technologies for processing hard-to-enrich raw materials are energy-intensive, require a high consumption of reagents, or do not allow achieving high enrichment rates.This paper shows the results of studies aimed at solving the problem of increasing the efficiency of beneficiation of oxidized copper ores using a modified reagent for sulfidizing oxidized copper ores, which does not require forced heating of the pulp and the use of separate equipment. The results of the conducted flotation studies indicate the effectiveness of using the modified reagent in the beneficiation of oxidized copper ore of the Zhezkazgan deposit.