Journals →  Tsvetnye Metally →  2021 →  #2 →  Back

HEAVY NON-FERROUS METALS
ArticleName Understanding the zinc discharge from sodium sulphate solution in the presence of surfactants
DOI 10.17580/tsm.2021.02.03
ArticleAuthor Kozlov P. A., Kolesnikov A. V., Nesmelov V. Yu.
ArticleAuthorData

UMMC-Holding Corp, Verkhnyaya Pyshma, Russia:

P. A. Kozlov, Deputy Director Responsible for Research, UMMC Technical University, Professor, Doctor of Technical Sciences, e-mail: p.kozlov@tu-ugmk.com

 

Chelyabinsk State University, Chelyabinsk, Russia:
A. V. Kolesnikov, Head of the Department of Analytical and Physical Chemistry, Doctor of Technical Sciences, e-mail: avkzinc@csu.ru

 

Chelyabinsk Zinc Plant PJSC, Chelyabinsk, Russia:
V. Yu. Nesmelov, Head of the Engineering Centre, Candidate of Technical Sciences, e-mail: vun@zinc.ru

Abstract

This paper aims to understand the effect of surfactants on zinc discharge in sulphate solutions on a solid electrode and to collect new experimental data that would give a deeper insight into the processes involved in industrial electrolysis. Anionic and cationic coagulants (flocculants) and an anionic frother were used as surfactants. Electrolysis was conducted in the potential region of –1050 to –1250 mV (Ag/АgCl) in stationary and dynamic conditions in sodium sulphate solution under intensive stirring. The authors obtained comparative data on the zinc discharge current in electrolyte with and without frother at the scan velocities of 2 to 100 mV/sec. It is noted that at higher scan velocities (>10–20 mV/sec) and in the initial electrolysis phase the zinc discharge process develops in a mixed mode. In this case, as the study showed, the positive effect of the frother on zinc discharge is most distinguished. A reaction order was designed based on zinc ion with four potentials to prove that the zinc electrowinning process develops in a mixed mode. It is shown that the addition of frother raises the reaction order from 1.2 to 1.5, which is attributed to a larger effective cathode surface area. The data obtained in a galvanostatic mode under intensive stirring conditions indicate that, at the current density of 1.7 mA/cm2, the electrode polarization is 1.6 times lower in the presence of cationic coagulant and almost 3 times lower in the presence of anionic coagulant. The data given in this paper are also indicative of a changing electrolysis mode. Under stirring, a transition is observed from a diffusion mode of zinc ion reduction to a mixed one. The experimental data obtained under intensive stirring conditions in sodium sulphate solution with frother, as well as anionic and cationic coagulants are in line with the theory of electrochemical processes.

keywords Zinc, current density, potential, voltamperogram, polarization, scan velocity, exchange current, flocculants, lignosulphonate, sodium sulphate, reaction order
References

1. Grigoriev V. D., Fulman N. I. Effect of polyacrylamide on zinc electrolysis parameters. Tsvetnye Metally. 1976. No. 5. pp. 24–25.
2. Grigoriev V. D., Fulman N. I. Effect of pyridine on zinc current yield. Tsvetnye Metally. 1974. No. 9. pp. 14–15.
3. Minotas J. C., Djellab H., Ghali E. Anodic behavior of copper electrodes containing arsenic or antimony as impurities. Journal of Applied Electrochemistry. 1989. Vol. 19, No. 5. pp. 777–783.
4. Laitinen H. A., Onstott E. I. Polarography of copper complexes. III. Pyrophosphate complexes. Journal of the American Chemical Society. 1950. Vol. 72, No. 10. pp. 4724–4728.
5. Drweesh M. A. Effect of surfactants on the removal of copper from waste water by cementaion. Alexandria Engineering Journal. 2004. Vol. 43, No. 6. pp. 917–925.
6. Kolesnikov A. V. Understanding the effect of di-(2-ethyl hexyl) phosphoric acid on the recovery of zinc from acid solutions by electrowinning. Butlerovskie soobshcheniya. 2018. Vol. 55, No. 8. pp. 127–133.
7. Kolesnikov A. V., Kozlov P. A., Fominykh I. M. Understanding the effect of White Spirit on the recovery of zinc from acid solutions by electrowinning. Butlerovskie soobshcheniya. 2018. Vol. 55, No. 8. pp. 120–126.
8. Kolesnikov A. V. Understanding why lignosulphonate can be efficiently used in zinc electrolysis. Butlerovskie soobshcheniya. 2014. Vol. 40, No. 12. pp. 110–116.
9. Kolesnikov A. V. Zinc sulphate solutions and cathodic and anodic processes in the presence of surfactants. Izvestiya Vysshikh Uchebnykh Zavedenii, Seriya Khimiya i Khimicheskaya Tekhnologiya. 2016. Vol. 59, Iss. 1. p. 53.
10. Galyus Z. Theoretical foundations of electrochemical analysis. Moscow : Mir, 1974. 552 p.
11. Kolesnikov A. V., Kozlov P. A. Zinc electrolysis in sulphate solutions. Tsvetnye Metally. 2018. No. 8. pp. 45–49.
12. Minin I. V., Solovieva N. D. The kinetics of zinc recovery from sulphate electrolyte in the presence of surfactants. Vestnik SGTU. Khimiya i Khimicheskie tekhnologii. 2013. No. 1. pp. 58–60.
13. Atkins P. Physical chemistry. Vol. 2. Moscow : Mir, 1980. 584 p.
14. Scorcelleti V. V. Theoretical electrochemistry. Leningrad : Khimiya, 1974. 567 p.

Language of full-text russian
Full content Buy
Back