Next Article in Journal
Studies with Rheological Behavior of Composite Lithium-Based Magnetorheological Grease
Next Article in Special Issue
Effective Deoxidation Process of Titanium Scrap Using MgCl2 Molten Salt Electrolytic
Previous Article in Journal
Effect of Grain Refinement on the Dynamic, Mechanical Properties, and Corrosion Behaviour of Al-Mg Alloy
Previous Article in Special Issue
Copper Cathode Contamination by Nickel in Copper Electrorefining
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Modelling the Effect of Solution Composition and Temperature on the Conductivity of Zinc Electrowinning Electrolytes

Department of Chemical and Metallurgical Engineering (CMET), Aalto University School of Chemical Engineering, P.O. Box 16200, FI-00076 Aalto, Finland
Boliden Odda Zinc Smelter, Eitrheim, NO-5750 Odda, Norway
Author to whom correspondence should be addressed.
Metals 2021, 11(11), 1824;
Received: 21 September 2021 / Revised: 25 October 2021 / Accepted: 9 November 2021 / Published: 13 November 2021
(This article belongs to the Special Issue Electrorefining in Sustainable Metals Production)


Zinc electrowinning is an energy-intensive step of hydrometallurgical zinc production in which ohmic drop contributes the second highest overpotential in the process. As the ohmic drop is a result of electrolyte conductivity, three conductivity models (Aalto-I, Aalto-II and Aalto-III) were formulated in this study based on the synthetic industrial electrolyte conditions of Zn (50–70 g/dm3), H2SO4 (150–200 g/dm3), Mn (0–8 g/dm3), Mg (0–4 g/dm3), and temperature, T (30–40 °C). These studies indicate that electrolyte conductivity increases with temperature and H2SO4 concentration, whereas metal ions have negative effects on conductivity. In addition, the interaction effects of temperature and the concentrations of metal ions on solution conductivity were tested by comparing the performance of the linear model (Aalto-I) and interrelated models (Aalto-II and Aalto-III) to determine their significance in the electrowinning process. Statistical analysis shows that Aalto-I has the highest accuracy of all the models developed and investigated in this study. From the industrial validation, Aalto-I also demonstrates a high level of correlation in comparison to the other models presented in this study. Further comparison of model Aalto-I with the existing published models from previous studies shows that model Aalto-I substantially improves the accuracy of the zinc conductivity empirical model.

1. Introduction

Zinc is widely used in the production of a number of key materials and applications, including brass, galvanized steel, sacrificial anodes, and batteries. Currently, more than 80% of the world’s primary zinc is produced through hydrometallurgical processes that typically incorporate electrowinning as the final step. Zinc electrowinning is normally conducted at a temperature between 30 and 40 °C in a zinc sulfate electrolyte that is composed of H2SO4 (150–200 g/dm3), Zn (50–70 g/dm3), Mn (4–8 g/dm3), and other impurities such as Mg and Ca. The main reactions during the electrowinning process are zinc deposition on the cathode (Equation (1)) and oxygen evolution on the anode (Equation (2)), although hydrogen evolution as an additional side reaction may also decrease the current efficiency at the cathode (Equation (3)).
Cathode :   Zn 2 + + 2 e Zn     E 0 = 0.76   V   vs .   SHE
Anode :   2 H 2 O 4 H + + O 2 + 4 e                   E 0 = + 1.23   V   vs .   SHE
Cathode :   2 H + + 2 e H 2                                             E 0 = 0   V   vs .   SHE
where E0 is the standard potential of the reaction and SHE is the standard hydrogen electrode.
Under normal process conditions, hydrogen evolution is reduced to a minimum rate in order to avoid excessive current usage; therefore, the overall reaction that occurs in the electrowinning cell and thermodynamical cell voltage (ET) can be outlined as in Equation (4):
Zn 2 + + H 2 O Zn + 2 H + + 1 2 O 2 E T = 1.99   V
In practice, total cell voltage (Ecell) is the sum of thermodynamical cell voltage (ET) and several overpotentials related to the cathodic and anodic reactions (Eη), the ohmic drop of the electrolytes (Eohmic), and the resistance of the electric circuit (ER), Equation (5):
E c e l l = E T + E η + E o h m i c + E R
Industrial zinc electrowinning processes are generally operated at a total cell voltage of 3.3–3.5 V, with a current density in the range of 400–600 A/m2 and typical current efficiencies of 89–92% [1]. Since the anodic reaction contributes more than 1.9 V of the total cell voltage [1], previous research has primarily focused on the development of new anode materials for reducing the oxygen evolution reaction (OER) overpotential [2,3,4,5,6,7,8,9,10]. Nevertheless, Pb-Ag alloys remain the most widely utilized anodes due to their low cost and favorable corrosion resistance properties in sulfuric acid media [11,12].
Electrolyte ohmic drop is the second most significant contributor to the total energy consumption in electrowinning and it is affected by both electrolyte conductivity and inter-electrode distances [13]. When the electrolyte is the medium for electrical current (I) flow, Ohm’s law can be written as Equation (6), where Eohmic and Relec are the ohmic drop and resistance, respectively. In addition, the electrolyte resistance, as a function of specific conductivity (κ) (as the inverse of specific resistivity (ρ)), can be written as Equation (7):
E o h m i c = I · R e l e c
R e l e c = ρ · l A = l ( κ · A )
By combining Equations (6) and (7), the ohmic drop voltage can be formulated as in Equation (8):
E o h m i c = I · l ( κ · A ) = j · l κ
where j is current density, l is inter-electrode distance. A is the area of electrode and l is the inter-electrode distance.
Meanwhile, the fundamental correlation of conductivity to electrolyte concentration is shown in Equation (9) [14]:
κ = l A ( F 2 R T ) i z i 2 D i C i
where zi is the valence, Di is the diffusion coefficient and Ci is the concentration (mol/dm3), F is the Faraday constant (96485 C/mol), R is the universal gas constant (8.314 J⋅K−1⋅mol−1), and T is the absolute temperature (K).
Several previously published conductivity models are shown in Equations (10)–(14) [15,16,17,18,19]:
κ N i k i f o r o v = 123 + 189.3 [ H 2 S O 4 ] 77.8 [ Z n ] + 1.14 T
κ S c o t t   e t   a l = 320 + 2.7 [ H 2 S O 4 ] ( T 35 ) + 196 ( [ H 2 S O 4 ] 1.12 ) 111 ( [ Z n ] + [ M n ] + [ M g ] + 0.5 [ N H 4 + ] 1.25 )
κ M a h o n   e t   a l = 107.9 [ Z n ] 539.0 [ H 2 S O 4 ] 18.14 [ Z n ] 2 63.80 [ H 2 S O 4 ] 2 10.27 [ Z n ] [ H 2 S O 4 ] + 167.3 [ Z n ] 2 [ H 2 S O 4 ] + 0.585 [ Z n ] ( T + 273 ) + 124.6 [ Z n ] [ H 2 S O 4 ] 2 67.62 [ Z n ] 2 [ H 2 S O 4 ] 2 + 3.345 [ H 2 S O 4 ] ( T + 273 ) 1.341 [ Z n ] [ H 2 S O 4 ] ( T + 273 )
κ T o z a w a   e t   a l = 4 + 1.15 T + 2.82 [ H 2 S O 4 ] T + 344.2 [ H 2 S O 4 ] 45.1 [ H 2 S O 4 ] 2 + 28.6 ( [ Z n ] + [ M g ] ) 2 + ( [ Z n ] + [ M g ] ) ( 1.14 T 105.8 [ H 2 S O 4 ] 22.4 )
κ A l i o f k h a z r a e i = 0.741 [ Z n ] 0.004857 [ H 2 S O 4 ] 2 + 2.453 [ H 2 S O 4 ] + 84.602 log T + 0.726 T + 24.023
where κ is in mS/cm, all concentrations are in g/dm3, and temperature T, is in °C.
From the modelling studies above, it can be recognized that from a fundamental perspective, that conductivity is a sum of the individual effects related to temperature T, acid concentration [H2SO4], and metal ion concentrations. Nevertheless, the previously published models have two major weaknesses: Firstly, the exclusion of minor impurities [15,16,17], and secondly, the utilization of a single coefficient value to represent zinc and other impurities [18,19]. Recent conductivity modelling studies in copper and silver electrolytes have demonstrated that every metal element ion present has an independent coefficient that can affect the electrolyte conductivity [20,21,22]. As a result, the main objective of this study is to develop an improved zinc electrolyte conductivity model, increasing prediction accuracy by taking into account the independent effects of metal impurities—such as Mn and Mg—along with the typical process parameters of zinc concentration, acidity, and temperature.

2. Materials and Methods

Conductivity measurement experiments were conducted with a series of synthetic electrolytes over a range of chemical compositions and temperatures that were selected as being representative of typical industrial zinc electrowinning processes (Table 1). Electrolytes were prepared using zinc sulfate (ZnSO4·7H2O, ≥99%, VWR Chemicals, Belgium), Magnesium sulfate (MgSO4·7H2O, ≥99.5%, Merck KGaA, Germany), Manganese sulfate (MnSO4·H2O, ≥99.5%, VWR Chemicals, Belgium), and sulfuric acid (H2SO4, 95–97%, Merck, Germany). All solutions were prepared with Millipore Milli-Q deionized water (≤2 μS/cm at 25 °C, EMD Millipore, Finland). The temperature of the electrolytes was controlled by a MGW Lauda MT/M3 circulating water bath (LAUDA, Lauda-Königshofen, Germany).
Conductivity measurements were performed using a Knick Portamess® 913 Cond conductivity meter (Knick Elektronische Messgeräte GmbH & Co. KG, Germany). Prior to measurement, the conductivity meter was calibrated in a standard reference solution (Reagecon, Ireland) with a conductivity of 12.88 mS/cm at 25 °C.
The design software MODDE 8.0 (MKS Data Analytics Solutions, Sweden) was utilized for experimental design and data analysis. Full experiments were designed using a linear model with the factors and levels outlined in Table 1, which resulted in a total of 30 individual conductivity measurements with three center points. Additionally, a further 19 measurements were conducted to help reduce any skewness of the data distribution. All models were evaluated using the following parameters: goodness of fit (R2), accuracy of prediction (Q2), standard deviation of the response (SDY), residual standard deviation (RSD), validity, and reproducibility values. Based on these parameters, a good mathematical model is required to have values of Q2, with validity and reproducibility values higher than 0.5, 0.25, and 0.5, whilst the difference between Q2 and R2 should be <0.3 [23].
Industrial validation of the models was conducted at Boliden Odda Zinc Smelter, Norway. As shown in Figure 1, four points of measurement were conducted in each of the four cells (A to D) investigated: at the inlet, 1/3 and 2/3 of the cell distance from the inlet, and the outlet. These points were selected to accommodate the possibility of any changes in acid and zinc concentrations induced by the electrowinning process. A sample of electrolyte was also taken for analysis from each point (Table 2) and further used for conductivity measurements at different temperatures.

3. Results and Discussion

The raw data obtained from conductivity measurements performed with the synthetic electrolyte solutions (Table S1) are shown in groups comprised of 5 mS/cm intervals in the related histogram (Figure 2). The figure shows that the data distribution is statistically symmetric and unimodal in nature; therefore, it provides an ideal basis for the development of the conductivity model.
Three models were developed, each with a distinctive character: Aalto-I (Equation (15)) was based on the assumption that each of the investigated parameters had an independent effect on the conductivity, while Aalto-II (Equation (16)) included the model with the interaction effects of concentration and temperature, as previously demonstrated by Scott et al., as shown in Equation (11) [18]. Finally, the Aalto-III (Equation (17)) was developed purely on the valid first-order full-factorial correlation of all parameters. This approach was taken by considering the previous model from Mahon et al., as shown in Equation (12) [16].

3.1. Aalto Conductivity Models

The three conductivity models in this study are shown in Equations (15)–(17), whilst the scaled and centered coefficients of these are shown in Figure 3.
κ A a l t o I = 129.239 2.657 [ Z n ] + 1.687 [ H 2 S O 4 ] + 5.658 T 2.802 [ M n ] 8.116 [ M g ]
κ A a l t o I I = 346.304 + 0.626 [ Z n ] 0.674 [ H 2 S O 4 ] + 0.6471 T 3.668 [ M n ] 7.372 [ M g ] 0.092 [ Z n ] T + 0.061 [ H 2 S O 4 ] T
κ A a l t o I I I = 135.072 + 9.924 [ Z n ] + 1.283 [ H 2 S O 4 ] + 4.692 T 26.705 [ M n ] 8.568 [ M g ] 0.028 [ Z n ] [ H 2 S O 4 ] 0.201   [ Z n ] T + 0.055   [ H 2 S O 4 ] T + 0.668 [ M n ] T
where concentrations are in g/dm3, T is the temperature in °C, and κ is in mS/cm.
From Figure 3, it can be seen that model Aalto-I clearly has valid coefficients throughout the parameters tested, whereas Aalto-II shows that there are valid correlations between both Zn and H2SO4 with temperature. Nevertheless, the correlation of the minor concentrations of Mn and Mg to the temperature was deemed to be insignificant, and was thus excluded from the final model. For the pure, full-factorial model of Aalto-III, a strong correlation is observed between Zn and H2SO4. Furthermore, similar to the Aalto-II, valid interrelation of the minor concentrations was not observed either with other concentrations, or the temperature.
In order to select the most representative out of these models, a comparison was conducted, as can be observed in Figure 4. All the models show very accurate predictions of conductivity, with strong values of R2, Q2, validity, and conductivity. Nevertheless, from the comparison, Aalto-I has the highest values for all the statistical value requirements; in particular, the related validity value is superior to those of the other two models. As a result, Aalto-I was selected as the proposed conductivity model from this study.
According to Aalto-I, increases in both temperature and H2SO4 have a positive effect on conductivity, whereas the presence of metal ions (Zn, Mn, Mg) has a negative impact on solution conductivity. These findings are in agreement with earlier studies of Zn electrowinning conductivity [15,24,25,26], and are similar to the behavior found for Cu, Ni, and As, in copper electrowinning electrolytes [22].

3.2. Comparison of Models with Synthetic Solutions

A comparison of the Aalto-I model with those available in the literature (Figure 5), demonstrates a significant improvement in the calculation accuracy. Interestingly, the model from Mahon et al. [16], with the second-order full-factorial correlation (Equation (12)), shows good accuracy whilst having lower linearity than the model Aalto-I. On the other hand, the model proposed by Scott et al. [18] shows excellent linearity, even though it results in much higher calculated conductivities than the observed values. The overcalculation of the Scott et al. [18] model may result from the fact that the coefficients of the metal ions are set to a single value, rather than allowing each different ion type to contribute individually, which results in the deviation of the values. In comparison, whilst Aalto-I is shown to have a slight advantage with synthetic electrolyte conductivity measurements, further validation of the real industrial electrolytes of the available models is required to determine the most representative model.

3.3. Industrial Validation

A further comparison of Aalto-I with the models from previous studies, based on the industrial electrolyte results (Table S2), was carried out, as shown in Figure 6. This comparison in the industrial electrolytes shows that the Aalto-I model quite clearly deviates from the other models examined. As can be seen in Figure 6, Aalto-I offers the best accuracy and linearity for the electrolyte qualities used in industry. The significance of the improvement can be seen with the help of the ideal (dotted) line, showing an ideal correlation (Y = x). In contrast, the presence of other concentrations in the real electrolyte that were not taken into account during the model development, such as Na and Ca, only result in a non-significant deviation.

3.4. Model Utilization

An approach to calculate the ohmic drop of the electrolyte (Eohmic) during zinc electrowinning can be conducted by combining the equation of model Aalto-I with Equation (8), as shown in Equation (18). The sensitivity analysis result with the center point: 60 g/dm3 Zn, 175 g/dm3 H2SO4, 4 g/dm3 Mn, 2 g/dm3 Mg, at a temperature of 35 °C, is shown by Figure 7. The selected value varied by ±15%, and its effect on the conductivity was observed.
E ohmic = j l ( 129.239 2.657 [ Zn ] + 1.687 [ H 2 S O 4 ] + 5.658 T     2.802 [ Mn ]     8.116 [ Mg ] )
where j is in mA/cm2, l is in cm, concentrations are in g/cm3, and T is in °C.
It can be seen that both the increase in [H2SO4] and T lowered the Eohmic value, whereas an increase in the concentration of metal ions (in particular Zn) increased the level of ohmic drop. The variation from the defined H2SO4 concentration (175 g/dm3 H2SO4) has the most significant influence on Eohmic in the investigated parameter magnitude, while the effects of T and [Zn] are slightly lower. These findings suggest that increases in temperature, and/or acid concentration, can be considered to effectively decrease the electrolyte ohmic drop.
In some cases, the bleeding of metal ions with high concentrations should also be considered to alleviate issues related to ohmic drop. For example, Boliden Odda Zinc Smelter has a relatively high acid concentration (ca. 190 g/L) and temperature (ca. 40 °C), and a low zinc concentration (ca. 50 g/L). Mn concentration in the electrolyte is maintained at between 7 and 8 g/dm3 in order to produce the MnO2 layer required for the corrosion protection of the Pb-Ag anodes [27,28,29]. However, the high concentration of Mg (11–12 g/dm3), besides causing the blockage of pipe systems [30,31,32] and difficulties in the mass-transfer process of zinc deposition [33], could also create extra electrolyte overpotential. From Aalto-I and Equation (18), approximately 15% of the electrolyte ohmic drop can be reduced by lowering the Mg concentration from 11.2 g/dm3 to 2 g/dm3. Furthermore, the model Aalto-I results based on the published data of Zn electrorefining show a large deviation of the ohmic drop contribution to the cell potential, from the lowest at app. 6.1%—as discussed by We et al.—to more than double for the highest contribution to cell potential of 14.8% (outlined by Yanqing et al.) [13,18,34,35,36,37,38,39,40,41,42,43,44], as shown in Table 3.
It is worth noting, however, that the above discussions are primarily focused on the cell voltage and ohmic drop, whilst optimal operating parameters are the complex result of many other factors. For instance, high acid concentration may increase the likelihood for hydrogen evolution, and reverse zinc dissolution, leading to a decrease in the current efficiency, while elevated temperature would cause nodule formation [18]. Consequently, the comprehensive effects of electrode reactions, and electrolyte ohmic drop, should be evaluated in detail during parameter optimization.

4. Conclusions

The three zinc electrolyte conductivity models constructed in this study were found to have good validities, and high correlation coefficients (Aalto I–III). Furthermore, Aalto-I was shown to offer a significant improvement to the accuracy of prediction when compared to the previously published models, due to the inclusion of individual coefficients for each metal present, rather than as a single collective effect of all metals. The industrial validation of the models—conducted at the Boliden Odda facility in Norway—further demonstrated the high accuracy of the Aalto-I conductivity model. Even though the effects of minor impurities (Na and Ca) were excluded during the development of the model, the model can accurately predict conductivity. This indicates that the parameters and levels taken into account within the model development were representatives of the real conditions present in industrial processes. Consequently, Aalto-I can be used as an effective tool for the prediction of electrolyte conductivity, and the optimization of industrial zinc electrowinning processes.

Supplementary Materials

The following are available online at, Table S1: Raw data obtained from the conductivity measurements of the synthetic zinc electrolytes. Table S2: Conductivity measurements of industrial electrolytes from the electrowinning cells at different temperatures.

Author Contributions

Z.W.: conceptualization, writing—original draft preparation; A.T.A.: writing—review and editing; B.P.W.: writing—review and editing; S.J. and M.M.: validation; M.L.: project administration, funding acquisition and resources. All authors have read and agreed to the published version of the manuscript.


GoldTail (project number, 319691); Symmet (project number, 2117441); Tocanem (project number, 2118451).

Data Availability Statement

Data regarding this article is available from the corresponding author upon a reasonable request.


Grateful thanks to Boliden Odda Zinc Smelter for allowing field measurements to be undertaken at their plant. The RawMatTERS Finland Infrastructure (RAMI) funded by Academy of Finland and based at Aalto University is also acknowledged.

Conflicts of Interest

The authors declare no conflict of interest.


  1. O’Keefe, T.J. Zinc electrowinning-short course. In Lead Zinc 2000 Symposium; John Wiley & Sons: Pittsburgh, PA, USA, 2000. [Google Scholar]
  2. Stefanov, Y.; Dobrev, T. Potentiodynamic and electronmicroscopy investigations of lead–cobalt alloy coated lead composite anodes for zinc electrowinning. Trans. IMF 2005, 83, 296–299. [Google Scholar] [CrossRef]
  3. Jin, L.; Huang, H.; Fei, Y.; Yang, H.; Zhang, H.; Guo, Z. Polymer anode used in hydrometallurgy: Anodic behaviour of PANI/CeO2/WC anode from sulfate electrolytes. Hydrometallurgy 2018, 176, 201–207. [Google Scholar] [CrossRef]
  4. Rashkov, S.; Dobrev, T.; Noncheva, Z.; Stefanov, Y.; Rashkova, B.; Petrova, M. Lead–cobalt anodes for electrowinning of zinc from sulphate electrolytes. Hydrometallurgy 1999, 52, 223–230. [Google Scholar] [CrossRef]
  5. Karbasi, M.; Alamdari, E.K.; Dehkordi, E.A. Electrochemical performance of PbCo composite anode during zinc electrowinning. Hydrometallurgy 2019, 183, 51–59. [Google Scholar] [CrossRef]
  6. Li, H.; Chen, Z.; Yu, Q.; Zhu, W.; Cui, W. Effects of tungsten carbide on the electrocatalytic activity of PbO2-WC composite inert anodes during zinc electrowinning. J. Electrochem. Soc. 2017, 164, H1064–H1071. [Google Scholar] [CrossRef]
  7. Zhang, C.; Liu, J.; Chen, B. Effect of CeO2 and graphite powder on the electrochemical performance of Ti/PbO2 anode for zinc electrowinning. Ceram. Int. 2018, 44, 19735–19742. [Google Scholar] [CrossRef]
  8. Chen, B.; Wang, S.; Liu, J.; Huang, H.; Dong, C.; He, Y.; Yan, W.; Guo, Z.; Xu, R.; Yang, H. Corrosion resistance mechanism of a novel porous Ti/Sn-Sb-RuOx/β-PbO2 anode for zinc electrowinning. Corros. Sci. 2018, 144, 136–144. [Google Scholar] [CrossRef]
  9. Zhang, T.; Morimitsu, M. A novel oxygen evolution anode for electrowinning of non-ferrous metals. In Electrometallurgy 2012; John Wiley & Sons, Ltd.: Pittsburgh, PA, USA, 2012; pp. 29–34. ISBN 978-1-118-37135-0. [Google Scholar]
  10. Morimitsu, M. Performance and commercialization of the smart anode, MSATM, for environmentally friendly electrometallurgical process. In Electrometallurgy 2012; John Wiley & Sons, Ltd.: Pittsburgh, PA, USA, 2012; pp. 49–54. ISBN 978-1-118-37135-0. [Google Scholar]
  11. Ivanov, I.; Stefanov, Y.; Noncheva, Z.; Petrova, M.; Dobrev, T.; Mirkova, L.; Vermeersch, R.; Demaerel, J.-P. Insoluble anodes used in hydrometallurgy: Part II. anodic behaviour of lead and lead-alloy anodes. Hydrometallurgy 2000, 57, 125–139. [Google Scholar] [CrossRef]
  12. Ivanov, I.; Stefanov, Y.; Noncheva, Z.; Petrova, M.; Dobrev, T.; Mirkova, L.; Vermeersch, R.; Demaerel, J.-P. Insoluble anodes used in hydrometallurgy: Part I. corrosion resistance of lead and lead alloy anodes. Hydrometallurgy 2000, 57, 109–124. [Google Scholar] [CrossRef]
  13. Alfantazi, A.M.; Dreisinger, D.B. The role of zinc and sulfuric acid concentrations on zinc electrowinning from industrial sulfate based electrolyte. J. Appl. Electrochem. 2001, 31, 641–646. [Google Scholar] [CrossRef]
  14. Brett, C.M.A.; Brett, A.M.O. Electrochemistry: Principles, Methods, and Applications; Oxford University Press: Oxford, UK, 1993; ISBN 978-0-19-855388-5. [Google Scholar]
  15. Aliofkhazraei, M.; Alamdari, E.K.; Zamanzade, M.; Salasi, M.; Behrouzghaemi, S.; Heydari, J.; Haghshenas, D.F.; Zolala, V. Empirical equations for electrical conductivity and density of Zn, Cd and Mn sulphate solutions in the range of electrowinning and electrorefining electrolytes. J. Mater. Sci. 2007, 42, 9622–9631. [Google Scholar] [CrossRef]
  16. Mahon, M.; Wasik, L.; Alfantazi, A. Development and implementation of a zinc electrowinning process simulation. J. Electrochem. Soc. 2012, 159, D486–D492. [Google Scholar] [CrossRef]
  17. Nikiforov, A.F.; Natarova, E.L. A formula to calculate the specific conductivity of zinc electrolyte. Tsvetnaya Metall. 1971, 44, 28. [Google Scholar]
  18. Scott, A.C.; Pitblado, R.M.; Barton, G.W.; Ault, A.R. Experimental determination of the factors affecting zinc electrowinning efficiency. J. Appl. Electrochem. 1988, 18, 120–127. [Google Scholar] [CrossRef]
  19. Tozawa, K.; Umetsu, Y.; Su, Q. World Zinc ’93, Proceedings of the International Symposium on Zinc. Australasian Institute of Mining and Metallurgy Publication Series 7/93, Hobart, Australia, 10–13 October 1993; Australasian Institute of Mining and Metallurgy: Parkville, Australia, 1993. [Google Scholar]
  20. Aji, A.T.; Kalliomäki, T.; Wilson, B.P.; Aromaa, J.; Lundström, M. Modelling the effect of temperature and free acid, silver, copper and lead concentrations on silver electrorefining electrolyte conductivity. Hydrometallurgy 2016, 166, 154–159. [Google Scholar] [CrossRef][Green Version]
  21. Lehtiniemi, I.; Kalliomäki, T.; Rintala, L.; Latostenmaa, P.; Aromaa, J.; Forsén, O.; Lundström, M. Validation of electrolyte conductivity models in industrial copper electrorefining. Min. Metall. Explor. 2018, 35, 117–124. [Google Scholar] [CrossRef]
  22. Kalliomäki, T.; Aromaa, J.; Lundström, M. Modeling the effect of composition and temperature on the conductivity of synthetic copper electrorefining electrolyte. Minerals 2016, 6, 59. [Google Scholar] [CrossRef][Green Version]
  23. Eriksson, L.; Johansson, E.; Kettaneh-Wold, N.; Wikström, C.; Wold, S. Design of Experiments: Principles and Applications; MKS Umetrics AB: Umeå, Sweden, 2008; Volume 2008, p. 78. [Google Scholar]
  24. Aliofkhazraei, M. Study of electrical conductivity for electrolytes of electrowinning and electrorefining processes. Russ. J. Non-ferrous Metals 2009, 50, 97–101. [Google Scholar] [CrossRef]
  25. Barton, G.W.; Scott, A.C. A Validated mathematical model for a zinc electrowinning cell. J. Appl. Electrochem. 1992, 22, 104–115. [Google Scholar] [CrossRef]
  26. Hinatsu, J.T.; Tran, V.D.; Foulkes, F.R. Electrical conductivities of aqueous ZnSO4−H2SO4 solutions. J. Appl. Electrochem. 1992, 22, 215–223. [Google Scholar] [CrossRef]
  27. MacKinnon, D.J.; Brannen, J.M. Effect of manganese, magnesium, sodium and potassium sulphates on zinc electrowinning from synthetic acid sulphate electrolytes. Hydrometallurgy 1991, 27, 99–111. [Google Scholar] [CrossRef]
  28. Mahon, M.; Alfantazi, A. Manganese consumption during zinc electrowinning using a dynamic process simulation. Hydrometallurgy 2014, 150, 184–191. [Google Scholar] [CrossRef]
  29. Mohammadi, M.; Alfantazi, A. Evaluation of manganese dioxide deposition on lead-based electrowinning anodes. Hydrometallurgy 2016, 159, 28–39. [Google Scholar] [CrossRef]
  30. Booster, J.L.; Van Sandwijk, A.; Reuter, M.A. Magnesium removal in the electrolytic zinc industry. Miner. Eng. 2000, 13, 517–526. [Google Scholar] [CrossRef][Green Version]
  31. Georgalli, G.A.; Eksteen, J.J.; Pelser, M.; Lorenzen, L.; Onyango, M.S.; Aldrich, C. Fluoride based control of Ca and Mg concentrations in high ionic strength base metal sulphate solutions in hydrometallurgical circuits. Miner. Eng. 2008, 21, 200–212. [Google Scholar] [CrossRef]
  32. Sharma, K.D. An approach to reduce magnesium from zinc electrolyte with recovery of zinc from disposed residue of an effluent treatment plant. Hydrometallurgy 1990, 24, 407–415. [Google Scholar] [CrossRef]
  33. Tian, L.; Xie, G.; Yu, X.-H.; Li, R.-X.; Zeng, G.-S. Effect of magnesium ion on the zinc electrodeposition from acidic sulfate electrolyte. Met. Mat Trans. A 2012, 43, 555–560. [Google Scholar] [CrossRef]
  34. Sorour, N.; Zhang, W.; Gabra, G.; Ghali, E.; Houlachi, G. Electrochemical studies of ionic liquid additives during the zinc electrowinning process. Hydrometallurgy 2015, 157, 261–269. [Google Scholar] [CrossRef]
  35. Zhang, Q.; Hua, Y. Effects of 1-Butyl-3-Methylimidazolium hydrogen sulfate-[BMIM]HSO4 on zinc electrodeposition from acidic sulfate electrolyte. J. Appl. Electrochem. 2009, 39, 261–267. [Google Scholar] [CrossRef]
  36. Tripathy, B.C.; Das, S.C.; Singh, P.; Hefter, G.T.; Misra, V.N. Zinc electrowinning from acidic sulphate solutions part IV1Part I, part II and part III Are Published in J. Appl. Electrochem, 27 (1997) 673, 28 (1998) 915, 29 (1999) 1229, respectively.1: Effects of Perfluorocarboxylic Acids. J. Electroanal. Chem. 2004, 565, 49–56. [Google Scholar] [CrossRef]
  37. Wu, X.; Liu, Z.; Liu, X. The effects of additives on the electrowinning of zinc from sulphate solutions with high fluoride concentration. Hydrometallurgy 2014, 141, 31–35. [Google Scholar] [CrossRef]
  38. Alfantazi, A.M.; Dreisinger, D.B. An investigation on the effects of orthophenylene diamine and sodium lignin sulfonate on zinc electrowinning from industrial electrolyte. Hydrometallurgy 2003, 69, 99–107. [Google Scholar] [CrossRef]
  39. Majuste, D.; Martins, E.L.C.; Souza, A.D.; Nicol, M.J.; Ciminelli, V.S.T. Role of organic reagents and impurity in zinc electrowinning. Hydrometallurgy 2015, 152, 190–198. [Google Scholar] [CrossRef][Green Version]
  40. Yanqing, L.; Liangxing, J.; Jie, L.; Shuiping, Z.; Xiaojun, L.; Hongjian, P.; Yexiang, L. A novel porous Pb–Ag anode for energy-saving in zinc electrowinning: Part II: Preparation and pilot plant tests of large size anode. Hydrometallurgy 2010, 102, 81–86. [Google Scholar] [CrossRef]
  41. Bouzek, K. Current distribution at the electrodes in zinc electrowinning cells. J. Electrochem. Soc. 1995, 142, 64. [Google Scholar] [CrossRef]
  42. Huang, H.; Zhou, J.; Chen, B.; Guo, Z. Polyaniline anode for zinc electrowinning from sulfate electrolytes. Trans. Nonferrous Met. Soc. China 2010, 20, s288–s292. [Google Scholar] [CrossRef]
  43. Chen, B.; Yan, W.; He, Y.; Huang, H.; Leng, H.; Guo, Z.; Liu, J. Influence of F-doped β-PbO2 conductive ceramic layer on the anodic behavior of 3D Al/Sn Rod Pb−0.75%Ag for zinc electrowinning. J. Electrochem. Soc. 2019, 166, E119–E128. [Google Scholar] [CrossRef]
  44. Wang, S.; Zhou, X.; Chi-Yuan, M.; Long, B.; Wang, H.; Tang, J.-J.; Yang, J. Electrochemical properties of Pb-0.6 wt% Ag powder-pressed alloy in sulfuric acid electrolyte containing Cl/Mn2+ ions. Hydrometallurgy 2018, 177, 218–226. [Google Scholar] [CrossRef]
Figure 1. Schematic illustration of cells in the tank house, and the in situ conductivity measurements and sampling points.
Figure 1. Schematic illustration of cells in the tank house, and the in situ conductivity measurements and sampling points.
Metals 11 01824 g001
Figure 2. Histogram of the specific conductivity measured from the synthetic zinc electrowinning solutions utilized in this study.
Figure 2. Histogram of the specific conductivity measured from the synthetic zinc electrowinning solutions utilized in this study.
Metals 11 01824 g002
Figure 3. Scaled and centered coefficients of different contributory factors for constructed models Aalto-I, Aalto-II and Aalto-III.
Figure 3. Scaled and centered coefficients of different contributory factors for constructed models Aalto-I, Aalto-II and Aalto-III.
Metals 11 01824 g003
Figure 4. Measured (synthetic Zn electrolyte) vs. predicted conductivity by models Aalto-I, II and III.
Figure 4. Measured (synthetic Zn electrolyte) vs. predicted conductivity by models Aalto-I, II and III.
Metals 11 01824 g004
Figure 5. Measured (synthetic Zn electrolyte) vs. predicted conductivity by Nikiforov et al. (1971), Scott et al. (1988), Mahon et al. (2012), Tozawa et al. (1993), and Aliofkhazraei et al. (2007) [15,16,17,18,19].
Figure 5. Measured (synthetic Zn electrolyte) vs. predicted conductivity by Nikiforov et al. (1971), Scott et al. (1988), Mahon et al. (2012), Tozawa et al. (1993), and Aliofkhazraei et al. (2007) [15,16,17,18,19].
Metals 11 01824 g005
Figure 6. Measured vs. predicted conductivity for industrial Zn electrolyte determined by the earlier published models of Nikiforov et al. (1971), Scott et al. (1988), Mahon et al. (2012), Tozawa et al.(1993) and Aliofkhazraei et al. (2007) [15,16,17,18,19] and by the current Aalto-I model.
Figure 6. Measured vs. predicted conductivity for industrial Zn electrolyte determined by the earlier published models of Nikiforov et al. (1971), Scott et al. (1988), Mahon et al. (2012), Tozawa et al.(1993) and Aliofkhazraei et al. (2007) [15,16,17,18,19] and by the current Aalto-I model.
Metals 11 01824 g006
Figure 7. Effect of variable changes on the level of ohmic drop (Eohmic) predicted by Aalto-I.
Figure 7. Effect of variable changes on the level of ohmic drop (Eohmic) predicted by Aalto-I.
Metals 11 01824 g007
Table 1. Parameters and levels use in this study.
Table 1. Parameters and levels use in this study.
[Zn2+ ] 50, 60, 70g/dm3
[H2SO4 ] 150, 175, 200g/dm3
[Mn2+ ] 0, 4, 8g/dm3
[Mg2+ ] 0, 2, 4g/dm3
T30, 35, 40°C
Table 2. Composition of industrial electrolytes obtained from Boliden Odda Zinc Smelter.
Table 2. Composition of industrial electrolytes obtained from Boliden Odda Zinc Smelter.
Sample IDCellPositionComposition (g/dm3)
Table 3. Zinc electrowinning operating conditions and calculated Eohmic.
Table 3. Zinc electrowinning operating conditions and calculated Eohmic.
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Wang, Z.; Aji, A.T.; Wilson, B.P.; Jørstad, S.; Møll, M.; Lundström, M. Modelling the Effect of Solution Composition and Temperature on the Conductivity of Zinc Electrowinning Electrolytes. Metals 2021, 11, 1824.

AMA Style

Wang Z, Aji AT, Wilson BP, Jørstad S, Møll M, Lundström M. Modelling the Effect of Solution Composition and Temperature on the Conductivity of Zinc Electrowinning Electrolytes. Metals. 2021; 11(11):1824.

Chicago/Turabian Style

Wang, Zulin, Arif Tirto Aji, Benjamin Paul Wilson, Steinar Jørstad, Maria Møll, and Mari Lundström. 2021. "Modelling the Effect of Solution Composition and Temperature on the Conductivity of Zinc Electrowinning Electrolytes" Metals 11, no. 11: 1824.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop