Copper Electrolysis Research Articles

Potential influence mechanism of Mn and Co ions in the process of electrowinning of copper

The presence of impurity ions in the electrolyte during copper electrolysis influences anode performance and cathode quality. Lead anode corrosion causes resource loss and environmental pollution, emphasizing the need to study these impurities. The effects of Co2+ and Mn2+ on Pb-0.06 %Ca-1.2 %Sn anodes and cathode copper are investigated, establishing optimal ion concentrations. Mn2+ facilitates the growth of MnO2 on the PbO2 surface, enhancing corrosion resistance and catalytic activity, especially at a concentration of 2 mg/L. Additionally, the presence of Co2+ leads to the formation of Co3O4 and MnO2, further improving corrosion resistance and promoting oxygen evolution. A pilot experiment with Mn2+ at 2 mg/L and Co2+ at 120 mg/L achieves a current efficiency of 98.4 % and reduces the cell voltage to 1.817 V, successfully meeting energy-saving and efficiency-enhancing objectives.

ELECTROSYNTHESIS OF Cu2O IN THE Cu(s)|CuSO4(aq)|Fe(s) REACTOR AND DEGRADATION POTENT FOR METHYLENE BLUE

Research on Cu synthesis2O uses the electrolysis method in the Cu(s)|CuSO4(aq)|Fe(s) system and degradation tests on methylene blue. Cu2O is a blackish-red solid which has properties as a semiconductor with a band gap of around 2-2.2 eV. These transition metal oxides are widely used as catalysts, solar cell components, and photodetectors. This research aims to synthesize Cu2O with variations in electrolysis time, determine the characteristics of Cu2O using FTIR and XRD, and test the degradation of methylene blue. The method used is electrolysis with a fixed potential and time variations. Research stages include solution preparation, determination of decomposition potential, electrolysis of samples under various conditions, and analysis. The results of determining the decomposition potential are used as the application potential value in the copper electrolysis process, namely 3.25 V. Sample electrolysis was carried out at a potential of 3.25 V, solution pH 4.0 in a volume of 100 mL at 30, 60, 90, and 120 respectively. and 150 minutes. The products obtained were analyzed using Fourier Transform Infra-Red (FTIR) and X-ray diffraction (XRD). The results of FTIR analysis show that before calcination there is a Cu-O functional group with a wave number of 477.23 cm-1 and after calcination, there is a Cu-O functional group with a wave number of 538.28 cm-1 which indicates the formation of oxide. The results of XRD analysis show that the value of 2θ before calcination is 36.553; 50,481 ; 62.855 which shows the peak of Cu and after calcination 29.928; 36,027 ; 61.568 shows the Cu2O peak. The highest photocatalytic activity test results for Cu2O against methylene blue were 85.96%. The rate of degradation of methylene blue by Cu2O follows the second order reaction rate equation with the R2 value and reaction rate constant being 0.9418 and 0.00769572 L mol-1 s-1, respectively.

Demand-side response power control strategy considering load production sequence requirements

With the introduction of a high proportion of new energy sources, the power system needs new means to enhance its regulating flexibility. High-energy-consuming industrial loads on the demand side have significant potential to improve the grid’s regulating flexibility. Unplanned power adjustments can affect normal load production. This paper proposes a power control strategy that considers the normal production order of loads, aiming to balance load response capacity requirements and safe production order. Taking copper electrolysis load as an example, based on the load process flow and the power characteristics of production equipment, factors affecting load production order and methods for calculating impact weights are analyzed, and a strategy to reduce the demand response to production order caused by power control is proposed. The effectiveness of the power control strategy is verified through simulation examples, providing a feasible solution for industrial loads to participate in demand-side response.

A novel method for rapid and highly selective removal of arsenic from copper electrolyte using zirconium salts

Copper electrolytes generally contain high concentrations of arsenic (As), which is very harmful in copper electrolytic production. In this paper, a zirconium salt, which selectively precipitated arsenic, was added to the electrolyte to realize rapid and efficient arsenic removal. The effects of zirconium salt addition, the reaction temperature, reaction time and different electrolytes on arsenic removal were systematically investigated, the concentration equilibrium curves for As and Zr were established at different temperatures, the effects of residual zirconium ions on copper electrolysis were evaluated, and a theoretical study of the arsenic removal process was carried out. The results showed that with the optimal conditions for arsenic precipitation, 85.41 % of the As was removed from the industrial electrolyte, and the As concentration in the electrolyte was decreased to 1.41 g/L. Regeneration of the precipitates was achieved in NaOH solutions, and the regenerated precipitates exhibited efficient As removal. The As–Zr reactions followed a third-order kinetics model, and the apparent activation energy was 36.42 kJ/mol. Furthermore, the As–Zr reaction pathway, transition state structure and microscopic valence bonding changes were investigated with density functional theory (DFT). This research provides a promising method for processing copper electrolyte with high contents of As.

On the problem of intensified decopperization of copper electrolysis slimes

On the problem of intensified decopperization of copper electrolysis slimes

Morbidity with temporal disability in workers engaged in refined copper production

Introduction. High ductility, electrical and thermal conductivity, and resistance to corrosion determine a high demand of the national economy for refined copper, thus necessitating a comprehensive study of the occupational environment and health status in workers employed in this branch of non-ferrous metallurgy. 
 The purpose of our study was to assess the morbidity with temporal disability in workers engaged in the fire and electrolytic refining of copper. 
 Materials and methods. Morbidity with temporal disability in both male and female workers was studied by means of its detailed personal record at one of the large copper refineries of the Middle Urals. 
 Results. Among those engaged in copper smelting, the highest morbidity with temporal disability rates per one hundred workers were registered among repairers and auxiliary personnel (95.3 sick leave episodes and 1,147.8 days) in men and among overhead crane operators (52.8 episodes and 657.6 days) in women. In the copper electrolysis shop, the highest rates were noted among both men (86.7 episodes and 954.0 days) and women (77.8 episodes and 841.2 days) constituting the core personnel. We established that in the study cohort lung diseases ranked first among the causes of the morbidity with temporal disability followed by musculoskeletal diseases.
 Limitations. Such a study is feasible only at the enterprises that record and measure morbidity with temporal disability due to work.
 Conclusions. Our findings may indicate work-relation of morbidity with temporal disability in male repairers and auxiliary personnel, as well as female crane operators engaged in fire refining of copper and in both male and female core personnel engaged in electrolytic refining.

Industrial validation of conductivity and viscosity models for copper electrolysis processes

In copper electrorefining and electrowinning, the conductivity and viscosity of the electrolyte affect the energy consumption, and for electrorefining the purity of cathode copper. Consequently, accurate models for predicting these properties are highly important. Although the modeling of conductivity and viscosity of synthetic copper electrolytes has been previously studied, only a few models have been validated with actual industrial electrolytes. The conductivity and viscosity models outlined in this study were developed using conductivity and viscosity measurements from both synthetic and industrial solutions. The synthetic electrolytes were investigated over a temperature range between 50–70 °C and typical concentrations of Cu (40–90 g/dm3), Ni (0–30 g/dm3), Fe (0–10 g/dm3), Co (0–5 g/dm3), As (0–63.8 g/dm3), H2SO4 (50–223 g/dm3) as well as other solution impurities like Sb in some cases. Validation of the synthetic electrolyte models was performed through industrial measurements at three copper plants across Europe. Generally, the developed models predicted the conductivities and viscosities of industrial solutions with high accuracy. The viscosity models covered extended ranges of both [H2SO4] and [Cu] with percentage errors of only (2.08 ± 0.59) - (2.48 ± 0.61). For conductivity, two different models for low (<142 g/dm3) and high (>142 g/dm3) [H2SO4] electrolytes were utilized. Their error margins were (−1.96 ± 0.84) - (−1.44 ± 0.35) and (1.17 ± 0.27) - (2.52 ± 0.28), respectively. In the case of high [H2SO4] electrolytes, the validations focused on conductivity, and the highest level of accuracy was obtained when the effects of Sb and other minor impurities were considered.

Short Circuit Fault Detection against High Thermal Background Using a Two-Level Scheme Based on DoG Filter

Short circuit is a key factor which drastically affects the efficiency of metal electrorefining. Infrared image of the intercell busbar region is used to perform short circuit detection. To cope with the high thermal background, a two-level short circuit detection method is designed. Firstly, with background subtraction, high intensity short circuit electrodes, as well as the background, are removed, and normal working electrodes are preserved. In the second stage, suspicious short circuit areas are sifted out by normal electrode detecting and texture period estimation. Gaussian difference filter (DoG) which is based on the human visual system is improved to match the target gray distribution. A comparative experiment indicates that the proposed orthogonal DoG outperforms the original DoG and top-hat in the accuracy of normal electrode detection. The two-level detection method in this paper is applied in a copper electrolysis plant and exhibits superiority in locating short circuits and avoiding miss detection.

Hydrometallurgical recovery of high-purity copper cathode from highly impure crude copper

A new hydrometallurgical route was investigated in which a pure copper cathode was recovered from crude copper containing high amounts of impurity elements. As an example of crude copper, copper powder obtained from a top submerged lance furnace, which was pulverized by atomization from molten copper, was used. The selective leaching of copper was achieved using an ammoniacal alkaline solution containing divalent copper ammine complexes and ammonium chloride with most impurities (e.g. silver and gold) remaining in the residue. However, some impurities, such as nickel, arsenic, antimony, and lead were dissolved. Purification steps using hydroxyapatite and magnesium chloride were effective at removing lead, antimony, and arsenic. On the basis of these results, copper cathode recovery from crude copper was examined. As a result, a sufficiently pure copper cathode was finally obtained by monovalent copper electrolysis, which indicated the possibility of using this process as a new route for recovering pure copper from highly impure crude copper.

Извлечение никеля из имитаторов пульп никелевого производства в процессе газофазной конверсии

A new approach to Ni removal from simulators of dump waste product of the industrial waste purification of the wet gas-cleaning plant and the copper electrolysis workshop at the Copper Plant (Polar branch PJSC MMC «Norilsk Nickel») is proposed. The method is based on gas-phase treatment of waste product with NOХ, HNO3, or NH3 vapors, followed by dissolution of Ni salt in water. It has been found out that using nitrating media, containing HNO3 (vapor), NOX and H2O (vapor), allowed us to perform the effective leaching of nickel from the pulp simulator volume. A possible disadvantage of the method is a simultaneous leaching of considerable amounts of calcium and sulfur.

Effect of Cyclical Flow Velocity on Magnetized Copper Electrolysis Process

Effect of Cyclical Flow Velocity on Magnetized Copper Electrolysis Process

Purification of crude selenium by vacuum distillation and analysis

In this study, metallurgical grade crude selenium (99.4%), comprehensively recovered from copper electrolysis anode slime, was purified to 99.992% through triple consecutive vacuum distillation (TCVD) on a laboratory scale. The actual evaporation rate and accommodation coefficient α of crude selenium were found to be 0.0231 g cm−2 min and 0.3236, respectively, at 523 K and approximately 4 Pa by a vacuum thermogravimetric furnace. Internal heat vacuum distillation equipment was employed in the purification experiments with a dynamic vacuum level of approximately 4 Pa. Detailed analysis of the initial and purified selenium was performed using inductively coupled plasma mass spectrometry (ICP-MS) to identify the 15 most common impurity elements. The analysis confirmed the reduction in the total impurity content from 2997.38 ppmw to <79.08 ppmw. The microscopic impurity elemental distribution was analyzed using an electron probe microanalyzer (EPMA), and it shows that the impurities were relatively concentrated and gathered in crude selenium. The results enrich the database of selenium evaporation kinetics and lay a foundation for the industrial purification of selenium.

Experimental analysis of the performance of innovative circulation configurations for cleaner copper electrolysis

A series of copper electrorefining tests were performed to determine the effects of circulation configuration, as well as inlet flow rate and current density, on impurity particle behavior and cathode purity. SEM/EDS was utilized to acquire surface characteristics and impurity distributions on the harvested cathode copper and the collected anode slimes. The anode slime weight distributions under different operating conditions were analyzed to determine the effects of the three factors on anode slime behavior. ICP was used to obtain the concentrations of major impurities in the harvested cathode copper, and the results of selected impurities (As, Sb, Bi) were statistically analyzed to determine the relationship between the factors and impurities concentrations. The circulation configuration was identified as the most significant factor based on the statistical results, with the innovative configuration of two upper-inlets/one lower-outlet as the optimal configuration. Furthermore, a theoretical discussion of the effects of these factors on slime particle behavior is given, which demonstrates that these factors have significant impact on slime particle transport by influencing species distribution, electrolyte density gradient, and fluid flow field in the cell. In addition, SEM/EDS results of collected slimes show that the innovative circulation configurations have the advantage of converting more suspended slime particles to settled slimes.

Controlling the deposition of silver and bimetallic silver/copper particles onto a carbon nanotube film by electrodeposition-redox replacement

The electrodeposition-redox replacement (EDRR) process was studied to control the creation of copper and silver containing particles on the surface of a carbon nanotube film. Synthetic solutions simulating typical hydrometallurgical copper electrolysis process solutions (40 g/L Cu, 120 g/L H2SO4) with different dilute concentrations of silver (1–10 ppm) were utilized as the source for particle deposition and recovery. Such process solutions are currently underutilized for use as a potential source for the deposition of noble particles. The effect of deposition voltage, deposition time, stirring, and redox replacement time between deposition pulses were investigated as the parameters affecting the morphology and composition of the deposited particles as well as deposition kinetics. The results showed that pure copper particles can be deposited when the redox replacement time between deposition pulses is very short (t = 2 s). By increasing the redox replacement time (t = 50 s and more) the original copper particle composition transforms into a core-shell structure with an outer layer predominately consisting of silver or a bimetallic mix of copper and silver, depending on the deposition conditions. The bimetallic Cu/Ag particle size could be controlled from 200 to 840 nm by the applied deposition voltage. At high redox replacement times (t = 150 s and more) the resulting particles were shown to be pure silver with a small diameter from 100 to 250 nm.

Diffusion coefficient of cupric ion in a copper electrorefining electrolyte containing nickel and arsenic

Diffusion and convection are the main modes of mass transport that occur during copper electrorefining. Diffusion determines the rate of copper transfer across the diffusion layer, which in turn, affects the dissolution of the anode and deposition on the cathode. The diffusion coefficient of cupric ion (DCu(II)) is a typical property that can be defined from the limiting current density (jlim) values. In this work, the limiting current densities were measured for 24 different synthetic copper electrolytes over a temperature range of 50–70 °C using a rotating disc electrode (RDE). From this data, a model for jlim and the corresponding models for DCu(II) were constructed using Levich (Model L), Koutecký-Levich (Model K) and mixed-control Newman equations (Model M). The models for jlim and DCu(II) were designed, refined and analyzed using the modeling and design tool MODDE, with the temperature, copper, nickel, arsenic and sulfuric acid concentrations as variables. Results from this research show for the first time that an increase in arsenic concentration has a reciprocal effect on the DCu(II) under copper electrorefining conditions. Furthermore, the models were validated with 11 industrial electrorefining electrolytes with known compositions. Model L (DCu(II) based on Levich equation) was shown to provide the highest correlation with the industrial solutions when compared to the other models (Model K and M) considered and previously published diffusion coefficient models. Overall, this work provides an explanation for the previously observed data variances in the literature, investigates for the first time the combined effect of parameters on DCu(II) value in industrial copper electrolysis and clarifies the effect of arsenic on the DCu(II) of copper electrorefining electrolytes.

Reviews the research on some dimensionally stable anodes (DSA) based on titanium

The metal mixed oxides (MMO) such as RuO2, IrO2, TiO2 as excellent catalysts on the surface of dimensionally stable anodes (DSAs) preparing by aqueous solutions of platinum-group metals (PGMs) chlorides for the copper electrolysis has been discussed. One of the possible surface modifications of the new titanium DSAs could be the alloying of the PGMs at low temperatures. This possibility has been described using the synthesis of catalysts for the reaction of crotonaldehyde hydrogenation and their characterization. The discussed results are related to the increase of current density by using alternative types of anodes and charge transfer between specific PGMs as well as chemical reaction engineering, and surface acidity in the catalysts.

Korozija i zaštita betona u pogonu za proizvodnju katodnog bakra

The most complex type of corrosion in the plants of Copper Smelter and Refineries in Bor is present in the plant of Electrolytic Copper Refinery, where the solution of copper (II) sulfate causes the corrosion of concrete and concrete reinforcement as well as the applied steel materials. The processes of corrosion and destruction of concrete surfaces are particularly pronounced. Corrosion of concrete reinforcement is recognized as the main cause of degradation the concrete structure in many cases, both under the influence of sulfates and the influence of chloride ions. Regarding to this, the protection system also requires a knowledge on corrosion problems, both steel and concrete surfaces. The protection system applied in the Copper Electrolysis Plants consists of laying the acid-resistant plates in the epoxy mass, on a previously primed concrete base. This protection system provides minimum 10 years of a protection durability. This work will present the problems of corrosion of concrete structures that occur daily in the plants of Copper Electrolytic Refinery in Bor, the method they are solved and the method of applying the protection systems.

Selenium extraction out of metallurgical production middlings

A short review of well known and currently used in production sector methods of selenium-containing slurries processing of copper and nickel productions are provided in this paper. The process flow scheme of copper anode slime processing at the Balkhash copper-smelting plant of Kazakhmys Smelting LLP is provided. The copper anode slime obtained after copper electrolysis is processed in the Kaldo furnace at the refining section of the precious metal shop where the metal roasting, smelting and converting are combined. The main product of the Kaldo furnace is the Dore alloy to refine gold and silver. Raw selenium containing ~ 80% of the main component, copper telluride and bag filter fines containing precious metals except for selenium are obtained as a by-product. While Kaldo furnace operation, the exhaust service gases pass through the gas trapping and treatment system. The current gas treatment system consists of three in series connected devices, such as a gas scrubber cooler (a quenching tower or a cooling tower), a Venturi scrubber and a cyclone separator. When gas trapping process the fines is deposited, selenium dioxide and arsenic trioxide are dissolved, and some metal chlorides are absorbed in the circulation solution. The 15 m3 of pulp with 40-50 g/dm3 of solid substance, and 20-50 g/dm3 of selenium in the solution, 2-5 g/dm3 of chlorine, the pH value is from 0 to 1 is formed after all stages of service gases trapping and treatment in the circulation tanks. After the metal hydroxides are deposited, the pulp is going through filter and sent to the selenium sedimentation stage. The precipitate after filtration (Venturi slurry) is a recycled product and is processed in a Kaldo furnace. Selenium precipitation is performed at a 70 °C temperature with sulfur oxide (IV) within 6-10 hours. Selenium obtained under this scheme was segregated in the smelting furnace and then vacuum distillated. As a result of these a brand metal with main component content of more than 99.5 % corresponding to the ST1 brand under GOST 10298-79 intended for export was obtained.

An Infrared Image-based Copper Electrolysis Short-Circuit Detection Method using Improved DoG Filter

Infrared image-based copper electrolysis short-circuit detection is a very difficult task because of compact distribution of electrodes and environment disturbance. The electrode hanger bars in the busbar area of the copper electrolysis cell are used as the direct diagnosis basis for short-circuit detection. To distinguish the hanger bars, which are small and dim targets with special shape, an improved DoG filter is proposed. First based on the prior shape information, a new target parameter model is proposed. Then the corresponding filter operator is used for DoG scale space constructing. The target model can more accurately matches with the filter operator and increase the detection accuracy. Most normal work hanger bars detected, according the detected hanger bar, short circuit ones can position indirectly. With this method, missing detection of short-circuit can be avoided.

Изучение влияния поверхностно-активных веществ на начальную стадию электроосаждение меди

In this research, the effect of surface-active substances (CMC and DFP) on the electrolysis of copper by cyclic voltammetry (CVA) and chronoamperometric methods was studied. The working electrode was a glassy carbon electrode. Studies show that in the acid solution of copper sulfate (10-2 M CuSO4 + 0.5 M H2SO4), the three-dimensional electrochemical deposition of copper occurs by the mechanism of instantaneous nucleation. The added surface active substances affect the dischargeionization process, the standard electroreduction potential is shifted to the negative side. The added DFP reduces the cathodic peak current, and the addition of CMC results in its increase. At the deposition potentials corresponding to the regions up to the CVA peak current (here, still, the mixed electrodeposition kinetics), the number of nuclei formed is greater for a pure solution, but at current decay potentials, where the diffusion regime takes place, the nuclei population density (NPD) is higher for solutions with surfactants. The most powerful effect here is caused by the addition of DFP. In the case of mixed additives, the NPD values are close to those of the CMC, obviously indicating the preferential adsorption of CMC, whereas the DFP as complexes with copper ions is closer to the near-electrode region.