Copper Extraction Process Research Articles

Design and Comparison of Fractional-Order Controllers in Flotation Cell Banks and Flotation Columns Used in Copper Extraction Processes

This work explores efficiency improvements in the copper flotation stage, a complex nonlinear, multivariable process subject to numerous perturbations. The primary objective is to design a fractional-order PID (FOPID) control strategy and a fractional-order model reference adaptive control (FOMRAC) system. The parameters for these controllers are optimized using the particle swarm optimization (PSO) algorithm with an objective function tailored to the control goals. This study employs models of both a bank series of five flotation cells and a flotation column. Their performance results are compared against traditional controllers, such as an integer-order PID and MRAC. The findings reveal that fractional-order controllers offer notable advantages over their integer-order counterparts, showing improved performance metrics with minimal changes to the existing control framework. This research highlights the effectiveness of fractional control in enhancing flotation processes and introduces a novel application of fractional control techniques in this area.

A NOVEL HYBRID DECISION-MAKING MODEL: FUZZY AHP-TOPSIS APPROACH FOR PRIORITISING COPPER SMELTING PROCESSES

The construction of a copper smelting facility and its undisturbed and profitable business undoubtedly contribute to the development of each country’s economy. These facilities employ many workers and produce a large amount of copper, reducing imports and dependence on this important raw material, thereby improving the economic situation in a given country. More than a hundred copper smelters operate worldwide, many of which use different types of copper extraction processes. Strict legislation relating to ecology and environmental protection as well as stakeholder involvement in selecting and constructing copper smelting facilities limit the maximisation of short-term economic objectives. The prioritisation of technological processes for the extraction of copper must consider the impacts of often mutually opposing economic, technical and environmental objectives. No research from the available literature analyses the economic, technical and environmental parameters systematically. Studies have mainly dealt with exploring individual influences of factors through the use of one selection method. This paper presents the development of a novel hybrid AHP-TOPSIS model in fuzzy environments that will provide both informative decisions and optimum results of decision making.

Degradation of hydroxyoxime CP-150 in the presence of nitrate and permanganate ions causing detrimental effect on copper extraction

Hydroxyoxime is the most widely used extractant in copper hydrometallurgy. However, due to the unstable structure of hydroxyoxime and the complex and harsh actual operating environment of the copper extraction system, the failure of hydroxyoxime in the copper extraction process due to degradation is of great concern. Currently, most studies mainly focus on verifying the influence of various potential factors on the degradation of hydroxyoxime extractants without considering the operation of the whole system, resulting in its failure problem not being effectively solved. In this paper, the operation of the extraction system was systematically analyzed with the issue of degradation failure of hydroxyoxime extractant in copper extraction and recovery process in the comprehensive recovery of gallium‑germanium copper in Shenzhen Zhongjin Lingnan Nonfemet Co., Ltd. Combining the effects of (i) acidity, (ii) copper ion concentration, (iii) NO3− and (iv) MnO4−, the effect of NO3− on extractant degradation was found to be more prominent, and the nitrification degradation (ND) rate was greatly affected by concentration and temperature. The MnO4− ion is a strong oxidant at high acidity. Its role on oxidation degradation (OD) of hydroxyoxime extractants was limited during the actual operation, overturning the common perception that strong oxidizing MnO4− is the leading cause of OD of hydroxyoxime extractants. Controlling the operating temperature of the extraction process is essential to prevent extractant degradation. In addition, GC–MS and FITR analysis of complex degradation products further validated the hydroxyoxime ND mechanism, which is of great practical significance for controlling the degradation of hydroxyoxime extractant in the copper extraction and recovery process from the origin.

Kinetic mechanism of copper extraction from methylchlorosilane slurry residue using hydrogen peroxide as oxidant

Copper was extracted from methylchlorosilane slurry residue by a direct hydrogen peroxide leaching method. A number of experimental parameters were analyzed to determine the extraction efficiency of copper. The extraction efficiency of copper reached 98.5% under the optimal leaching conditions, such as the hydrogen peroxide concentration of 1.875 mol·L−1, the leaching temperature of 323 K, the liquid–solid ratio of 20 ml·g−1, and the stirring speed of 300 r⋅min−1. The leaching kinetics of the copper extraction process was then described by the shrinking core model. There were two stages. The first stage was controlled by chemical reactions, while the second stage was controlled by interface transfer and product layer diffusion. The activation energy and kinetic control equations were determined, as well as an explanation of the leaching mechanism of copper extraction based on kinetic analysis and materials characterization. Copper resources can be recovered from the methylchlorosilane slurry residue efficiently and inexpensively with the methods used in this study.

Microbiological Processing of a Porphyry Copper Ore and Mineralogical Analysis of Solid Residues

The treatment of porphyry copper ores which are considered an important source of non-ferrous and precious metals requires the development of high-efficient technologies for metal extraction ensuring a low impact on the environment. The goal of the present work was to study the feasibility of a biohydrometallurgical approach for the processing of Kajaran porphyry copper-molybdenum ore as no attempt was done previously for microbiological processing of the mentioned ore. Sulfide and oxide ore samples used for bioleaching tests contained 0.63 and 0.77% copper, 1.81 and 1.55% iron, and 0.14 and 0.023% molybdenum, respectively. The experiments were carried out in 250 ml flasks under shaking conditions. Indigenous and adapted bacterial consortia ‘Kashen’ and ‘Kavart’ were used for bioleaching of ore samples. The objectives of the study were to investigate the influence of particle size (PS), pulp density (PD), and adaptation of the bacterial cultures to the process of copper extraction. The composition of feed material and leaching residues from bioleaching experiments were characterized by geochemical, mineralogical, and particle analyses. As a result, nearly complete bioleaching of the sulfide and oxide ores could be achieved after the optimization of the experiments. The particle analyses showed an enhanced liberation of chalcopyrite particles out of the intergrown ore under bioleaching conditions compared to the abiotic controls and hence an improved Cu solubilization under bioleaching conditions.

Bioleaching Process for Copper Extraction from Waste in Alkaline and Acid Medium

Flotation wastes are becoming a valuable secondary raw material and source of many metals and semimetals worldwide with the possibilities of industrial recycling. The flotation tailings contain oxide and sulfide minerals that have not been sufficiently stabilized and form acidic mine waters, which in turn contaminate groundwater, rivers, and reservoi6sediments. An effective way to recycle these mine wastes is to recover the metals through leaching. While the focus is on acid bioleaching by iron- and sulfur-oxidizing bacteria, alkaline leaching, and the removal of iron-containing surface coatings on sulfide minerals contribute significantly to the overall environmental efficiency of leaching. For this study, static and percolate bioleaching of copper from flotation waste at the Bor copper mine in Serbia was investigated in alkaline and then acidic environments. The aim of the study was to verify the effect of alkaline pH and nutrient stimulation on the bioleaching process and element extraction. A sample was taken from a mine waste site, which was characterized by XRF analyses. The concentration of leached copper was increased when copper oxide minerals dissolved during alkaline bioleaching. The highest copper yield during alkaline bioleaching was achieved after 9 days and reached 67%. The addition of nutrients in acidic medium enhanced the degradation of sulfide minerals and increased Cu recovery to 74%, while Fe and Ag recoveries were not significantly affected. Combined bioleaching with alkaline media and iron- and sulfur-oxidizing bacteria in acidic media should be a good reference for ecological Cu recovery from copper oxide and sulfide wastes.

Failure Mechanism of Hydroxyoxime Cp-150 in the Copper Extraction Process

Failure Mechanism of Hydroxyoxime Cp-150 in the Copper Extraction Process

Evolution of moisture in tailings dams located in arid climates. Case study: Castaño Viejo mine, San Juan, Argentina

This paper presents the results obtained in geotechnical exploration campaigns carried out in mining tailings dams resulting from the extraction process of lead, zinc and copper. The studied dams have been abandoned for more than half a century and are located in the Andes Mountains, San Juan, Argentina, an area characterized by water deficit regimens. The observation of degrees of saturation, which is surprisingly high in the internal zones of the tailings dams, led to a long-term field experiment (plot test) to investigate the observed behaviour. Based on the results of the plots test, we have concluded that stratigraphy controls the evolution of the water stored with the tailings. Clay and silty layers develop high degrees of saturation due to the capillary barrier effect, whilst the interlayers of sand dry up to a residual saturation condition. This situation inhibits the capillary rise and the diffusion of vapour, thus isolating the interior of the tailings from the atmosphere. It was observed that the depth of the active layer is 10 to 35 cm for evaporation and 35 to 75 cm for infiltration in the plot experiment. Such asymmetry determines a net flow of water into the system, which is consistent with the generation and conservation of a high degree of saturation within the tailings.

The BRISA process as a path for efficient copper recovery from waste PCBs

In the present work, a two-stage biohydrometallurgical process for copper extraction from waste PCBs is developed. The main goal of this study is to check whether to separate the chemical leaching of copper with ferric iron from the regeneration of the leaching agent by bacterial oxidation of the ferrous iron is an efficient route for copper recovery from waste PCBs. To test this proposal, large waste PCBs pieces were retained in a stirred tank reactor (STR) in contact with a leaching liquor circulating at a high flow rate between this STR and a bioreactor.The kinetics of leaching of large PCB pieces, when ferric iron is added in excess over the stoichiometric requirements, is limited by the rate of mass transfer of the leaching agent. A heterogeneous kinetic model was proposed to fit the experimental data. It was also found that by increasing the ferric iron concentration the leaching rate was increased.Process separation has proven to be a promising configuration in which the productivity of the bioreactor has fulfilled the leaching agent demand and 90% of copper extraction was achieved in 48 h for large waste PCBs.

Extraction of copper from complex carbonaceous sulfide ore by direct high-pressure leaching

The increase of impurities and complexity of copper ores are among the recent challenges in the mining industry. Complex carbonaceous sulfide ores are extremely difficult to treat due to their mineralogical complexity and impurities of organic carbon and carbonates. This study focuses on the development of a hydrometallurgical process for efficient copper extraction from complex carbonaceous sulfide ore which contains chalcopyrite, carbonates (dolomite and calcite), and carbonaceous gangue minerals. Characterization of the ore sample and leach residues was conducted using XRD and EPMA analysis, while ICP-OES was used for the determination of total dissolved metals in solution. High-pressure leaching of complex carbonaceous sulfide ore in oxygenated sulfuric acid solution was performed and the influence of leaching parameters such as sulfuric acid concentration, temperature, total pressure, and pulp density was studied. The extraction of copper increased with increasing temperature, sulfuric acid concentration, and total pressure. On the other hand, an increase in pulp density resulted in a decline in copper extraction due to an increased slurry viscosity and resistance in the diffusive mass transfer of reactants. Selective dissolution of copper from iron can be achieved by controlling free acidity in the pregnant leach solution (PLS). Under these leaching conditions: 100 g/L, 1 M H2SO4, 160 °C, 1.0 MPa total pressure, the highest copper and iron extractions achieved were 97.55% and 95.37%, respectively. Precipitation of copper from the PLS by NaSH sulfidization was investigated and more than 99.9% of copper was recovered at a Cu: NaSH molar ratio of 1:1.8.

Purification of concentrated waste water of pcb production from copper ions

In modern conditions, it is important to create a comprehensive technology for processing wastewater containing copper compounds, with the disposal of precious metals, the organization of circulating water supply of the enterprise and obtaining safe for disposal sludge. Methods of sewage treatment of galvanic productions are considered.
 The results of experimental studies of the process of copper extraction from water by cementation on iron powder particles under static conditions are presented. The technological scheme of the reactor-cementator is given. The influence of various factors on the process of copper cementation – pH, concentration and ratio of iron and copper in the reaction mixture, contact time were studied. The time at which the greatest rate of change of residual copper concentration is observed is determined. The influence of the pH value of the cementation process was also determined. As a result of the obtained data, it is concluded that the concentration of hydrogen ions in the solution affects the course of the contact exchange reaction. The higher the acidity of the solution, the higher the recovery rate of copper. Promising directions for the creation of closed water circulation systems in the process of copper wastewater treatment are outlined.

Selective leaching of copper from waste printed circuit boards (PCBs) using glycine as a complexing agent

<p>In this research, the selective leaching of copper from waste printed circuit boards (PCBs) using glycine as a complexing agent was investigated. PCBs were pulverized and sieved, which allowed obtaining a PCBs powder of particle size fraction ≤ 1mm. The PCBs powder has been characterized by several techniques before and after leaching. In order to understand the copper extraction process, the reaction mechanisms, and to determine the optimal leaching parameters, the effects of a range of parameters during copper leaching were investigated, including leaching time, solid-to-liquid ratio, mechanical stirring rate, leaching temperature and glycine concentration. Copper leaching from PCBs waste powder was identified as a complex four-stage gas-liquid-solid process that is carried out slowly under ambient conditions. Glycine shows a very significant selectivity for copper during leaching process allowing dissolving copper from PCBs waste with a percentage of 92.8% under ambient conditions.</p>

One-step extraction of high-purity CuCl2·2H2O from copper-containing electroplating sludge based on the directional phase conversion

The recovery of heavy metals is a vital way to turn electroplating sludge into resources and reduce its environmental hazards. However, the complex compositions of the polymetallic electroplating sludge severely limit the selective recovery of metal resources such as copper. In this study, we took a kind of copper-containing electroplating sludge (C-ES) as an example present and investigated the process of copper extraction. The copper and other metals were directional converted through an accurate phase transformation process carried out by chlorination combined with thermal regulation. Eventually, the copper was selectively recovered in the form of CuCl2·2H2O, while the rest of the metals were converted into stable metal salts or oxides. The HCl solution was the best regulator for selective copper recovery. Under the optimal conditions, the recovery of copper approached 97% and the purity of the CuCl2·2H2O product was about 95%. The kinetic reaction equation of the CuCl2 volatilization process can be described by Power Low, G(α) = α1/15. The economic estimate based on experimentation indicates the profit of recycling CuCl2·2H2O is about $23.2/kg. This work provides a novel, simple, and efficient approach to the selective recovery of heavy metal from polymetallic solid wastes.

Extraction of Non-ferrous Metals from Underspoil Waters


 
 
 he focus of the study was the acidic underspoil waters of Safyanovskaya copper JSC containing 0.17 g/l of copper and 1.8 g/l of zinc (pH 2.8–2.9). The purpose of the work was research and development of water purification technology from impurities (copper, zinc, aluminum, iron, manganese), suggesting the possibility of copper and zinc extraction in the form of commercial products. The process of copper extraction by cementation with metallic iron was studied. It was shown that this method could allow to extract 94–95 % copper into a concentrate. The zinc extraction from solution after copper removal was studied by precipitation with NaHS, Na2CO3, NaOH and CaO. For economic reasons it is recommended to make zinc precipitation in two stages with CaO in order to produce cake containing 15–21 % Zn with extraction 80–87 %. This cake can be utilized at zinc processing plant. A process flowsheet for acidic underspoil waters, including copper cementation and the precipitation of zinc cake, has been developed. According to this scheme, mother liquor from zinc precipitation should be treated with lime until pH reaches 10–10.5, followed by pulp settling. As a result, purified water of the following composition is obtained, mg/l: zinc – 0.05, copper – 0.01, aluminum – 0.02, iron – 0.02, manganese – 0.05.
 Keywords: underspoil water, copper, zinc, iron, cementation, calcium oxide, concentrate, precipitation
 
 

Efficient removal of arsenic from copper smelting wastewater via a synergy of steel-making slag and KMnO4

Copper smelting wastewater, one of the most significant sources of arsenic pollution from the copper extraction process of arsenic-associated minerals, seriously impedes the attainment of sustainable industrial development due its tremendous disposal cost and the potential risks it poses. Steel-making slag can effectively detoxify low arsenic-bearing wastewater, but its low removal rate, low adsorption capacity, and high arsenic concentration limit its large-scale application. In the study, we propose a cost-effective and feasible strategy for the disposal of high arsenic-bearing wastewater from copper smelting plant via a synergy of steel-making slag and permanganate (KMnO4). Steel-making slag dissolved in wastewater releases Fe, Ca, and Si ions while simultaneously increasing the pH value of the solution. Afterward, As(III) and Fe(II) are oxidized to As(V) and Fe(III) in situ through the permanganate, generating an amorphous FeAsO4 precipitate and As-adsorbing Fe(OH)3 flocs. The dissolution and oxidization reaction is driven by a mutually improved cycle of reduction-generated H+ and MnO2, ensuring the continuous precipitation and adsorption of As. In this study, the synergy between steel-making slag and KMnO4 successfully achieved an arsenic removal rate of 91.37% and an arsenic removal capacity of 32.37 mg/g with an initial arsenic concentration of 1834 mg/L and a sulfuric acid concentration of 2800 mg/L. In combination with the adjustment of the pH value, subsequently, residual Fe, Ca, and Si ions were further hydrolyzed in the form of new Fe(OH)3 flocs and a Ca2SiO4 gel, promoting the deep purification of the wastewater. The final residual arsenic concentration achieved was 1.54 mg/L at a pH value of 10. Based on this study case, a process by which cooper smelting wastewater can be successfully treated via the synergy of steel-making slag and KMnO4 is proposed, which is potentially feasible for industrial application.

New Solvent Extraction Process of Nickel and Copper by D2EHPA in the Presence of Carboxylates

In the present study, for the first time, the effect of sodium acetate, sodium citrate, and the addition of sodium oxalate was investigated in the D2EHPA system for the extraction of nickel and copper. In this study, the optimum condition including pH, the concentrations of additives, and time was found according to the separation factor and the extraction efficiencies. In this regard, the best extractant/extractants or their mixtures were found. Furthermore, the slope analysis was applied to understand the mechanism of extraction. According to the results, the system containing an optimum concentration of sodium oxalate and a mixture of sodium acetate and sodium oxalate could be used to separate copper from nickel and nickel from copper, respectively.

Optimisation of biohydrometallurgical batch reactor process for copper extraction and recovery from non-pulverized waste printed circuit boards

The electronic waste is the fastest-growing solid waste all over the world. The printed circuit board (PCB), an essential part of all the electronic waste is a potential source of various metals thus known as “Urban-mine”. In this paper, a novel approach to enhance the extraction of copper from non-pulverized waste printed circuit boards (WPCBs) was carried out. WPCBs pre-treatment with NaOH for removal of the epoxy coating was optimized before the bioleaching process. The pretreatment resulted in the exposure of the metal present on WPCBs. Copper was extracted by two-step bioleaching process. In the first step ferric sulphate was biogenerated by Leptospirillum ferriphilum dominating iron oxidizing consortium with 1196.0 mg/L/h of average ferrous sulphate oxidation rate. In the second step, the biogenerated ferric iron was used for copper extraction from a single plate as well as from multiple plates in scale-up studies. In the scale-up study, 3 batches of eleven WPCB plates at a time were studied and an average 168 ± 1.3 g copper was recovered at the end of the process, which corresponds to 99% leaching. The recovered copper was precipitated from the leachate by the cementation process using iron scrap and almost 99% copper was recovered after the process. The developed process shows the potential to be applied at commercial scale for recovery of metals and the management of electronic waste which leads to conservation of resources and environment.

Sustainable copper extraction from mixed chalcopyrite–chalcocite using biomass

Abstract This paper elaborated on the sustainability of the copper extraction process. In fact, an alternative copper extraction route from mixed sulphide ores, chalcopyrite and chalcocite using mesophilic biomass consortium at 33.3 °C and ferric leaching process were attempted. Bioleaching experiments were settled with a fraction size of −75+53 µm. Bacteria were used as the catalyst. A copper yield of 65.50% was obtained. On the other hand, in ferric leaching process, with a fraction size of −53+38 µm, when the temperature was increased to 70 °C, the copper leaching rate increased to 78.52%. Thus, comparatively, the mesophilic bioleaching process showed a more obvious advantage in copper extraction than leaching process with a high temperature. However, it has been resolved from the characterization performed using SEM−EDS, FTIR and XRD observations coupled with different thermodynamic approaches that, the indirect mechanism is the main leaching mechanism, with three transitory mechanisms (polysulphide, thiosulphate and elemental sulphur mechanisms) for the mixed chalcopyrite−chalcocite ore. Meanwhile, the speciation turns into Cu2S−CuS−Cu5FeS4−Cu2S before turning into CuSO4. While ferrous oxidation and the formation of ferric sulphate occur, and there is a formation of strong acid as bacteria digest sulphide minerals into copper sulphate at low temperature, which is why this copper production scenario requires a redox potential more than 550 mV at room temperature for high copper leaching rate.

Life-cycle assessment of solar integrated mining processes: A sustainable future

The negative impact of the mining industries on climate change, human health and ecosystems, arises from extensive use of fossil fuels. This could be mitigated by the integration of solar energy systems into mining processes, such as the use of solar industrial process heating systems in low-temperature mining processes. This paper estimates the resultant environmental impacts, which could result from the partial use of solar process heating in the aluminum, copper, ilmenite, rutile, lead, nickel, and uranium mining and extraction processes. The extensive analysis presented here contains multiple scenarios such as using flat plate solar collector and evacuated tube solar collector for process heat generation, including the base case scenario using fossil fuels. The novel analysis has quantified the overall reduction of environmental impacts on different categories of aquatic ecotoxicity, terrestrial ecotoxicity, carcinogens, non-carcinogens, and global warming. The analysis is done using SimaPro (version 8.5) utilising the IMPACT 2002 + method for 15 midpoints indicator-based categories and four endpoint indicator-based categories. The analysis results reveal valuable information regarding comparative impacts between the two types of solar collector considered and show that evacuated tube collectors would be more beneficial for environmental emission reduction.

Isolasi Mikroba Dari Air Asam Tambang Pada Area Pertambangan Tembaga Di Pulau Wetar, Provinsi Maluku

This research was conducted to find bacteria from the genus Acidithiobacillus ferrooxidans which isolated from mine acid water in the copper mining area on Wetar Island, Maluku Province. This bacterium will be utilized in the biohidrometallurgical process (bioleaching) for copper extraction in mining area. The results of this study indicate that bacteria can be isolated from mine acid water samples by enrichment method that was use liquid media from Leathen which is optimized using Trypton Soya Broth (TSB) and bacterial growth on solid media. The presence of Thiobacillussp bacteria was confirmed by the results of gene analysis using a 16S rRNA sequence showing the presence of mixed bacterial colonies but not a single colony.