Copper Sulfide Ore Research Articles

Development of metallurgy of copper and copper alloys in China in the 2nd millennium BC

The first rare metal finds in China are dated to the Neolithic period, but most of them belong to its final phase. For this period, pure copper is known, very rare arsenic alloys, probably smelted from ore with arsenic admixtures. At the beginning of the 2nd millennium BC, in Gansu, the technology of smelting ore with the following alloying with arsenic, occasionally tin minerals were borrowed from an unknown source. This technology spread to the east, and is present in the Erlitou II layer. At the beginning of the Erlitou III phase (which corresponds to the beginning of the Shang dynasty), the tradition of the Seima-Turbino metallurgy and the technology of smelting copper sulfide ores and alloying with tin penetrated into the Yellow River basin from the north (through Shanxi) from southern Siberia. This tradition soon spread to southern China, as well as the western and northern peri-phery of Chinese civilization. The penetration of the Karasuk tradition of arsenic alloys is also observed in the west and north in the late Shang period, and the Shang and Karasuk metallurgical traditions coexisted there. A special situation formed in Xinjiang, where the Andronovo tradition of smelting sulfide ores and tin alloys pene-trated, but this penetration was limited to the west of the region. It did not affect the development of Chinese me-tallurgy. In general, in China, there is the same correspondence between the types of used ores and alloys as in the rest of Eurasia: native copper and malachite — pure copper, oxidized ores and secondary sulfides with gangue — arsenic copper, occasionally tin bronze, copper-iron sulfides — tin bronze. But in China, this sequence was driven by two technological impulses at the beginning of the 2nd millennium BC (from an unclear source) and at the end of the second half of the 2nd millennium BC from southern Siberia. In addition, during the late Shang period, the interaction of the Shang and Karasuk traditions occurred in the north and west.

The Challenges and Prospects of Recovering Fine Copper Sulfides from Tailings Using Different Flotation Techniques: A Review

Flotation is a common mineral processing method used to upgrade copper sulfide ores; in this method, copper sulfide mineral particles are concentrated in froth, and associated gangue minerals are separated as tailings. However, a significant amount of copper is lost into tailings during the processing; therefore, tailings can be considered secondary resources or future deposits of copper. Particle–bubble collision efficiency and particle–bubble aggregate stability determines the recovery of target particles; this attachment efficiency plays a vital role in the selectivity process. The presence of fine particles in the flotation circuit is because of excessive grinding, which is to achieve a higher degree of liberation. Complex sulfide ores of markedly low grade further necessitate excessive grinding to achieve the maximum degree of liberation. In the flotation process, fine particles due to their small mass and momentum are unable to collide with rising bubbles, and their rate of flotation is very slow, further lowering the recovery of target minerals. This collision efficiency mainly depends on the particle–bubble size ratio and the concentration of particles present in the pulp. To overcome this problem and to maintain a favorable particle–bubble size ratio, different techniques have been employed by researchers to enhance particle–bubble collision efficiency either by increasing particle size or by decreasing bubble size. In this article, the mechanism of tailing loss is discussed in detail. In addition, flotation methods for fine particles recovery such as microbubble flotation, column flotation, nanobubble flotation, polymer flocculation, shear flocculation, oil agglomeration, and carrier flotation are reviewed, and their applications and limitations are discussed in detail.

A clean separation process using pretreatment-flotation for refractory mixed concentrates

• A new pretreatment-flotation separation method for galena and chalcopyrite was developed. • The modification mechanism of S 2- conversion to SO 4 2- on galena surface was revealed. • Separation test results of Cu-Pb sulfide mixed concentrate validates the theoretical analysis. In this paper, a clean separation technique of galena and chalcopyrite that innovatively combined a sulfuric acid pretreatment with collector-free flotation was proposed. X-ray diffraction (XRD) analysis, Scanning Electron Microscopy (SEM) determination, Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) measurement, and flotation experiments were carried out to research on the surface differentiation of galena and chalcopyrite with sulfuric acid and the effect on their flotation performance. XRD analysis showed that significant characteristic peaks of a new species of lead sulfate (PbSO 4 ) were formed in galena after sulfuric acid pretreatment, while chalcopyrite was not affected at all. SEM analysis and floatability results confirmed the effect of sulfuric acid on selective oxidation of galena surface. ToF-SIMS results further provided strong evidence for the conversion of sulfur ions to sulfate ions on galena surface. Lead sulfate species formed on the pretreated galena were detected at a thickness of 0–80 nm, which led to its loss of hydrophilicity and floatability. The experimental results of pretreatment-flotation separation of galena-chalcopyrite mixture and copper-lead sulfide mixed concentrate were in good agreement with the theoretical analysis. The results showed that the new method could effectively and thoroughly separate lead sulfide from copper sulfide ore, and the sulfuric acid in this technology could be recycled in the periodic pretreatment process. This work can enrich the surface inhibition theory of galena by sulfuric acid and provide an effective way for the separation of lead-copper sulfide ore.

Sustainable Use of Copper Resources: Beneficiation of Low-Grade Copper Ores

The global market has announced copper as a modern energy metal and finds its extensive utilization in the construction industry, electrical wiring, power transmission lines, alloying, anticorrosive coating, heat exchangers, refrigeration tubing, etc. Copper ore is primarily beneficiated from sulphide mineral deposits. Due to high-grade copper sulphide deposit exhaustion, the focus has now shifted towards recovery from different lean-grade oxide and mixed ore deposits. The present paper summarizes the utilization of copper as a clean energy mineral and its importance in the current renewable energy sector. Extensive research has been carried out on the flotation of copper sulphide ore as compared to copper oxide and mixed type ores. Besides flotation, other beneficiation techniques (selective flocculation and gravity separation) are also discussed in the present review. A few novel pretreatment methods are currently being studied for copper ore to intensify the separation for higher productivity.

Saturated Dissolved Oxygen Concentration in in situ Fragmentation Bioleaching of Copper Sulfide Ores.

In situ fragmentation bioleaching is a promising way to perform deep mining safely, economically, and in an environmentally friendly manner, where oxygen plays a critical role in microbial growth and mineral dissolution. However, the lack of oxygen limits the implementation of in-situ fragmentation bioleaching. To overcome this limitation, aeration was proposed, with saturated dissolved oxygen concentration as an important indicator. Orthogonal experiments were conducted to measure saturated dissolved oxygen concentration at various temperature, pH, and electrolyte (ferrous sulfate, ferric sulfate, copper sulfate, and sulfuric acid) concentration conditions. Experimental data were analyzed by Python programming language and least squares method to obtain a saturated dissolved oxygen concentration model. Results showed that temperature had the most significant effect on oxygen solubility, which was concluded by comparing the results of surface fitting based on the least squares method. At 30–40°C, the saturated dissolved oxygen concentration decreased faster as metal ions concentration increased. The conjoint effect of the five variables on oxygen solubility showed that pH was linearly negatively related to oxygen solubility. Additionally, a mathematical model was also proposed to predict the saturated dissolved oxygen concentration in in situ fragmentation bioleaching of copper sulfide ores. This work enables bioleaching processes to be modeled and controlled more effectively.

Use of Alternative Water Resources in Copper Leaching Processes in Chilean Mining Industry—A Review

Due to the significant growth of the world population, the accelerated growth of economic industries in various countries, and improved living conditions, freshwater consumption has increased dramatically and is currently under critical pressure. Its good use and rationing are essential. Even though mining is an industry that consumes much less water than other industries, such as agriculture, surrounding communities are constantly questioned. This occurs mainly because mining deposits are generally found in arid areas where freshwater is scarce, forcing government authorities to regulate water use in mining processes more severely. Faced with this scenario, the mining industry has innovated the use of seawater and wastewater from processes for its production processes. In addition, various projects are under development to construct desalination plants and water impulsion systems of the sea; therefore, it is expected that seawater and/or wastewater in mining will continue to grow in the coming years. Among the main challenges faced in the use of these water resources in mining is: (i) the close relationship that exists between the use of seawater and energy consumption, transferring the problem of water scarcity to a problem of energy cost overruns; (ii) generation of greater integration between the use of water and sustainable energy; and (iii) brine management is economically expensive and technically challenging and, therefore, most desalination plants discharge untreated brine directly into the sea, causing an environmental impact. On the other hand, regarding the use of these water resources in leaching processes, there are very positive results for the dissolution of copper from sulfide minerals, where the wastewater from desalination plants presents better results than seawater due to its higher concentration of chloride ions, allowing it to work at higher redox potential values in order to increase copper dissolution. This manuscript is a bibliographic review in which finally, it is concluded that it is feasible to incorporate wastewater from water desalination plants in heap leaching processes for copper sulfide ores, as long as the cost of transfer from water desalination plants to mining sites can be supported.

Sulfide leaching of high-grade arsenic copper concentrates

Such factors as lower-grade copper ores, more demanding mining and technical conditions, and higher implementation costs for new development projects are typical for the Ural region in general and for the Uchalinsky Mining and Processing Plant (Uchalinsky GOK), developing tennantite-containing copper-sulfide ore reserves, in particular. Depending on the process flow design and the mineral composition of the ore, 10–70 % of arsenic is transferred into copper concentrates. The mass fraction of arsenic in the resulting copper concentrates may reach 2 %, significantly reducing the concentrate grade. Sulfide-alkaline leaching has been studied as a promising conditioning method for flotation copper concentrate. It ensures more effective arsenic removal and compliance of the final product with the requirements for further pyrometallurgical processing. The studies were carried out using a low-grade high-arsenic concentrate sample from the Uchalinsky GOK containing 16.04 wt. % Cu, 5.30 wt. % Zn, 1.36 wt. % As, and 0.19 wt. % S. It has been established that iron is predominantly occurring in the form of pyrite, with chalcopyrite and sphalerite unevenly distributed in its mass. The concentrate had high concentrations of fahlore minerals (tennantite, etc.). Studies were conducted to assess the effects of changes in the sulfide leaching process parameters (temperature, raw material size, NaOH and Na2S concentrations, solid-liquid ratio, duration) on the transfer of arsenic into the alkaline solution. The specific conditions have been established (t = 95 °C; Cm(NaOH) = 3.5 M, Cm(Na2S) = 1.5 M; solidliquid ratio = 5; duration of three hours or more) that ensure almost complete removal of arsenic from the flotation concentrate to obtain a conditioned copper product meeting the requirements of GOST R 52998-2008.

The Mechanism of the Effect of Pre-Magnetized Butyl Xanthate on Chalcopyrite Flotation

In this work, we applied the technology of magnetic treatment to the flotation of chalcopyrite. The mechanism of the effect of pre-magnetized butyl xanthate on chalcopyrite flotation was studied using monomineral flotation tests, adsorption tests, conductivity tests, Fourier transform infrared spectroscopy (FTIR), etc. The monomineral flotation test results showed that, after the magnetization pretreatment of butyl xanthate solution, the chalcopyrite flotation recovery was increased by nearly two percentage points, and the dosage was reduced by 4–10 mg/L at the same recovery. The adsorption, FTIR, dissolved oxygen, and conductivity test results all showed that the magnetization pretreatment increased the dissolved oxygen content and promoted the oxidation of butyl xanthate to double xanthate with better selectivity to chalcopyrite. An electrochemical analysis showed that the magnetization pretreatment of butyl xanthate reduced the corrosion potential and corrosion current density of chalcopyrite surface and inhibited the self-corrosion process of chalcopyrite surface. The flotation test results of actual copper sulfide ore showed that pre-magnetized butyl xanthate could increase the copper recovery of copper concentrate by 3.06 percentage points and the sulfur recovery of sulfur concentrate by nearly 3 percentage points, and effectively reduce the mutual content of copper and sulfur concentrates.

Hydrogen Peroxide in Reagent Regimes in Copper Sulphide Ore Flotation

Hydrogen Peroxide in Reagent Regimes in Copper Sulphide Ore Flotation

Hydrogen Peroxide in Reagent Regimes in Copper Sulphide Ore Flotation

Hydrogen Peroxide in Reagent Regimes in Copper Sulphide Ore Flotation

Theoretical justification of pneumatic separation for copper sulfide ore enrichment

Theoretical justification of pneumatic separation for copper sulfide ore enrichment

Effects of forced aeration on community dynamics of free and attached bacteria in copper sulphide ore bioleaching

Effects of forced aeration on community dynamics of free and attached bacteria in copper sulphide ore bioleaching

Secondary Phase Formation During Electrokinetic in Situ Leaching of Intact Copper Sulphide Ore

Secondary Phase Formation During Electrokinetic in Situ Leaching of Intact Copper Sulphide Ore

Chalcocite (bio)hydrometallurgy—current state, mechanism, and future directions: A review

There has been a strong interest in technologies suited for mining and processing of low-grade ores because of the rapid depletion of mineral resources in the world. In most cases, the extraction of copper from such raw materials is achieved by applying the leaching procedures. However, its low extraction efficiency and the long extraction period limit its large-scale commercial applications in copper recovery, even though bioleaching has been widely employed commercially for heap and dump bioleaching of secondary copper sulfide ores. Overcoming the technical challenges requires a better understanding of leaching kinetics and on-site microbial activities. Herein, this paper reviews the current status of main commercial biomining operations around the world, identifies factors that affect chalcocite dissolution both in chemical leaching and bioleaching, summarizes the related kinetic research, and concludes with a discussion of two on-site chalcocite heap leaching practices. Further, the challenges and innovations for the future development of chalcocite hydrometallurgy are presented in the end.

Comparison of environmental performance of modern copper smelting technologies

The fight against climate change has emphasized the importance of understanding the environmental performance of metal production technologies. This is especially true for copper whose consumption will increase significantly due to electrification and, therefore, understanding the associated footprint becomes essential. This study uses simulation-based life cycle assessment (LCA) together with a commercial flowsheet simulation program to compare several copper smelting technologies against each other when producing metallic blister copper from sulfide copper ore. The lowest LCA values for three concentrate compositions and three capacities were obtained for Flash Smelting technology with Peirce-Smith converting (FSF-PSC). The unit CO2 emissions decreased with increasing capacity. The reduction obtained when the capacity was doubled was 1–9%, depending on the technology. The main source of CO2 emissions was electricity generation, including the use for oxygen production. For instance, for FSF-PSC it accounted for 91% of the climate change when global data source was used for electricity, translating into an 80% reduction if non-fossil electricity was introduced. A reduction of up to 85% in climate change can be achieved by changing from the highest emission producing technology, the Side Blowing Furnace – Top Blowing Converter (SBF-TBC), to the lowest (FSF-PSC) and by using non-fossil electricity.

X-ray Computed Tomography Evaluation of Crushed Copper Sulfide Ore for Pre-concentration by Ore Sorting

X-ray Computed Tomography Evaluation of Crushed Copper Sulfide Ore for Pre-concentration by Ore Sorting

Industrial Heap Bioleaching of Copper Sulfide Ore Started with Only Water Irrigation

Sulfuric acid solution containing ferric iron is the extractant for industrial heap bioleaching of copper sulfides. To start a heap bioleaching plant, sulfuric acid is usually added to the irrigation solution to maintain adequate acidity (pH 1.0–2.0) for copper dissolution. An industrial practice of heap bioleaching of secondary copper sulfide ore that began with only water irrigation without the addition of sulfuric acid was successfully implemented and introduced in this manuscript. The mineral composition and their behavior related to the production and consumption of sulfuric acid during the bioleaching in heaps was analyzed. This indicated the possibility of self-generating of sulfuric acid in heaps without exogenous addition. After proving by batches of laboratory tests, industrial measures were implemented to promote the sulfide mineral oxidation in heaps throughout the acidifying stages, from a pH of 7.0 to 1.0, thus sulfuric acid and iron was produced especially by pyrite oxidation. After acidifying of the heaps, adapted microbial consortium was inoculated and established in a leaching system. The launch of the bioleaching heap and finally the production expansion were realized without the addition of sulfuric acid, showing great efficiency under low operation costs.

Environmental, economic and technological factors affecting Chilean copper smelters – A critical review

Chile is the world's leading copper producer (28.3%) and maintains approximately 23.0% of current global reserves. Chile is faced with a significant risk posed by its collection of the most unsustainable and antiquated smelter operations among major copper producers worldwide. Moreover, forecasts also indicate a trend toward higher proportions of copper sulphide ores that carry high impurities, especially arsenic. To achieve the planned production increases, improve competitiveness in the global market, and reduce reliance on international smelting capacities, Chile must make significant and justifiable investment into new and/or existing smelting operations through equipment modernization. The required investment for upgrades may be on the order of billions of dollars. This review analyzes current roadblocks faced by the Chilean copper smelters and potential solutions according to environmental, economic and strategic factors. Recent advances in smelting technologies have focused on flash and bath smelting; despite a general trend toward flash furnace systems, recent bath furnace methods (e.g. China's SKS-BBS) are equally promising, particularly for varying and complex feeds. Strategic policies should focus on regionalized, non-integrated custom smelters, which can handle ores from a variety of sources while reducing overall operating costs. The government must play a fundamental role to incentivise the investments necessary to develop new smelter operations and upgrade existing infrastructure. With a large portion of copper concentrate exports coming from privately owned mines, synergistic efforts with industry partners will be crucial to increase overall smelting capacity and position Chile as a global leader in the smelting of copper concentrates.

Linking molecular structures of yeast-derived biosurfactants with their foaming, interfacial, and flotation properties

Yeast-derived bola amphiphiles have attracted growing attention in various industrial sectors as green reagents. However, their physico-chemical properties relevant to mineral separation by froth flotation are poorly explored. To bridge this gap, we studied the foaming, interfacial, and flotation properties of acidic sophorolipid (ASL), acidic glucolipid (GL) and alcoholic glucoside (GS) obtained from strain engineering of the yeast Candida bombicola by molecular editing of the headgroups. Bench-scale flotation testing of a copper sulfide ore showed that ASL can effectively separate copper sulfides (85% recovery at 20% grade), GL is less effective (ca. 60% recovery and 13% grade), while GS is a poor collector. To understand this trend, we studied the interfacial and foaming properties of these three biosurfactants. The surface tension study reveals that, contrary to GS, self-assembly of both ASL and GL at the air–water interface is pH-responsive, suggesting that both the biosurfactants acquire a Π-shape. The dependence of the foaming properties of all the three surfactants on pH and concentration does not correlate with the trends in the static surface tension, suggesting the critical roles of dynamic factors, interfacial elasticity and interfacial viscosity. Hydrophobicity of djurleite (a model copper sulphide) in the presence of the three surfactants was assessed using the contact angle and Hallimond flotation methods. ASL and GL only float the pure mineral at alkaline pH, which is consistent with the contact angle data. In contrast, even though GS does not have a significant effect on contact angle, it floats djurleite in a wide pH range, which is explained by the mechanical entrainment of hydrophilic mineral particles in rich GS foams. Overall, these results demonstrate the potential of carboxylic bola biosurfactants for the recovery of copper sulfides from ores. They also bring new insights into the interfacial and foaming properties of bola biosurfactants, which can assist their introduction into other industries.

Experimental calibration methodology for numerical parameters in a DEM software based in granular material static tests

Simulations are one of the most used tools in different investigations and topics, being a powerful tool to replicate a real-life system or to solve real engineering problems without interrupting any process. To accomplish a reliable replication of the real system, it is necessary to make good assumptions in the numerical parameters selection of the simulation and its configuration. The main goal of this research is to propose a calibration methodology of numerical parameters based on static tests simulations in the Rocky-DEM software. A laboratory flow test experiment was developed to measure the repose (ar) and emptying (ae) angles of a granular material in a static state. In the simulation experiment, these angles are dependent of numerical parameters, such as the static friction coefficient (mf), the rolling coefficient (mr) and the adhesive distance (da). To get the best numerical parameters that explained the behavior in the laboratory experiment, an optimization procedure was done. Two materials were used for this research: chickpeas, for the development of the calibration methodology, and sulfide copper ore, to apply this methodology. The numerical parameters for the chickpeas experiment were mf = 0.183, mr = 0.105 and da = 0.938 [mm], resulting in ar = 31.23° and ae = 28.85°. These simulated angles have a variation of 2.85% and 3.03% with respect to the values obtained in the laboratory experiment. In the case of the mineral experimentation, a mf = 0.892 and mr = 0.269 were obtained, simulating a ar = 30.1° and ae = 42.31°. Also, these results have a variation of 2.84% and 3.65% with respect to the values of the angles measured in the laboratory model. As a conclusion of the study, DEM simulation is a powerful tool to predict the behavior of granular materials. However, it is necessary to use calibrated values and settings in the simulations to increase the accuracy of the results.