Industrial validation of conductivity and viscosity models for copper electrolysis processes

Funding Information: This research was performed within the SIMP (System Integrated Metal Production) project (grant number 2140/31/2013) of DIMECC (Digital, Internet, Materials & Engineering Co-Creation (Tampere, Finland)) and BATCircle project (grant number 4853/31/2018) supported by Business Finland. In addition, Taina Kalliomäki would like to thank the Emil Aaltonen Foundation and Arif T. Aji the LPDP, Indonesian Endowment Fund for Education, (grant number S-1440/LPDP.3/2015) for additional funding. The RawMatTERS Finland Infrastructure (RAMI) based at Aalto University and supported by Academy of Finland is also greatly acknowledged. Finally, the authors would like to acknowledge the personnel in Glencore Nikkelverk AS, Reference Tankhouses 2 and 3, and Boliden Harjavalta Oy for their assistance and for permission to publish the results. Publisher Copyright: © 2021 The Author(s)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) [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.Peer reviewe