The assessment of zinc precipitation from sulfate solutions using magnesium-rich ores

Document Type : Research Paper

Authors

1 Department of Metallurgy and Materials Engineering, Hamedan University of Technology, Hamedan, Iran.

2 Research Centre of Advanced Materials, Faculty of Materials Engineering, Sahand University of Technology, Sahand New Town, Iran.

3 Materials and Metallurgical Engineering Department, University of Zanjan, Zanjan, Iran.

10.22059/ijmge.2025.395591.595256

Abstract

This study systematically investigates the mechanisms and optimization of zinc precipitation from sulfate solutions using magnesium-containing ores. The dominant reaction pathway leads to the formation of zinc hydroxysulfate (Zn5(OH)6(SO4)2) at moderate pH (4–6.5), as confirmed by a consistent final pH of 6.5 in all experiments. Temperature critically influences reaction kinetics, with 80 °C identified as optimal for maximizing zinc recovery (73.4 %) and ensuring effective magnesium participation in precipitation reactions. Process efficiency is governed by ore dosage, where 100 g/L of magnesium-rich ore yields peak zinc recovery, beyond which marginal improvements occur. Time-dependent studies reveal that 150 minutes represents the practical equilibrium for zinc precipitation at 80 °C, achieving 73.4% recovery with diminishing returns thereafter. Key findings demonstrate that controlled parameters—pH 6.5, 80°C, 150-min reaction time, and optimized ore dosage—collectively enhance zinc recovery while minimizing reagent consumption and energy costs. Under the optimized conditions (T = 80°C, ore dosage = 100 g/l, time = 150 minutes), the magnesium content demonstrated a significant reduction from 7.0 g to 5.1 g, corresponding to an absolute decrease of 1.9 g (27.1% decrement), which clearly indicates effective magnesium participation in the precipitation process, where the combination of elevated temperature and controlled ore dosage synergistically enhanced magnesium removal efficiency while minimizing residual content, ultimately contributing to improved process performance.

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[1] Abutalebi, M. R., Saneie, M., & Moghaddam, J. (2019). Investigation on the Zn separation behavior from solution contain Mg from a leaching solution of zinc filter cake by Solvent Extraction. Metallurgical Engineering, 22(2), 96–103. https://doi.org/10.22076/me.2019.103493.1231
[2] Ashtari, P., Surani-Yancheshmeh, H., Karimi, S., & Saghafi Yazdi, M. (2025). Developing a facile process for cobalt recycling from zinc plant residues using various environmentally friendly reductants towards a green and sustainable application in water splitting. Journal of Industrial and Engineering Chemistry. https://doi.org/10.1016/j.jiec.2025.01.055
[3] Booster, J. L., Van Sandwijk, A., & Reuter, M. A. (2000). Magnesium removal in the electrolytic zinc industry. Minerals Engineering, 13(5), 517–526. https://doi.org/10.1016/S0892-6875(00)00032-7
[4] Cheng, C. Y., Zhang, W., & Pranolo, Y. (2010). Separation of Cobalt and Zinc from Manganese, Magnesium, and Calcium using a Synergistic Solvent Extraction System Consisting of Versatic 10 and LIX 63. Solvent Extraction and Ion Exchange, 28(5), 608–624. https://doi.org/10.1080/07366299.2010.499299
[5] Choi, Y. (2014). Production of zinc sulphate concentrates from a dilute zinc sulphate solution. Google Patents.
[6] Dutrizac, J. E. (2002). Calcium sulphate solubilities in simulated zinc processing solutions. Hydrometallurgy, 65(2–3), 109–135. https://doi.org/10.1016/S0304-386X(02)00082-8
[7] Georgalli, G. A., Eksteen, J. J., Pelser, M., Lorenzen, L., Onyango, M. S., & Aldrich, C. (2008). Fluoride based control of Ca and Mg concentrations in high ionic strength base metal sulphate solutions in hydrometallurgical circuits. Minerals Engineering, 21(3), 200–212. https://doi.org/10.1016/j.mineng.2007.09.010
[8] Gupta, C. K., & T. K. Mukherjee. (1990). Hydrometallurgy in extraction processes Vol. 1. CRC Press, 1.
[9] Habashi, F. (1997). Handbook of extractive metallurgy. Handbook of Extractive Metallurgy, Vol.2, 1.
[10] Haghighi, H. K., Moradkhani, D., & Salarirad, M. M. (2015). Separation of zinc from manganese, magnesium, calcium and cadmium using batch countercurrent extraction simulation followed by scrubbing and stripping. Hydrometallurgy, 154, 9–16. https://doi.org/10.1016/j.hydromet.2015.03.007
[11] Heimala, S. O. (1981). Process for electrolytic recovery of zinc from zinc sulfate solutions. Google Patents.
[12] Jin, X., Zhen, Y., Li, X., Du, M., Luo, X., Wei, C., Deng, Z., & Li, M. (2023). Removal of Magnesium in Zinc Hydrometallurgical System via Freezing Crystallization: From Laboratory Experiments to Industrial Application. Sustainability, 15(23), 16275. https://doi.org/10.3390/su152316275
[13] Karimi, S., Rashchi, F., & Moghaddam, J. (2017). Parameters optimization and kinetics of direct atmospheric leaching of Angouran sphalerite. International Journal of Mineral Processing, 162, 58–68. https://doi.org/10.1016/
j.minpro.2017.03.004
[14] Khanmohammadi Hazaveh, P., Karimi, S., Rashchi, F., & Sheibani, S. (2020). Purification of the leaching solution of recycling zinc from the hazardous electric arc furnace dust through an as-bearing jarosite. Ecotoxicology and Environmental Safety, 202, 110893. https://doi.org/
10.1016/j.ecoenv.2020.110893
[15] MacKinnon, D. J., & Brannen, J. M. (1991). Effect of manganese, magnesium, sodium and potassium sulphates on zinc electrowinning from synthetic acid sulphate electrolytes. Hydrometallurgy, 27(1), 99–111. https://doi.org/10.1016/0304-386X(91)90081-V
[16] Matthew, I. G., Newman, O. M. G., & Palmer, D. J. (1980). Water balance and magnesium control in electrolytic zinc plants using the E.Z. selective zinc precipitation process. Metallurgical Transactions B, 11(1), 73–82. https://doi.org/10.1007/BF02657174
[17] Mosayebi, H., Abdollahi, M., & Khalesi, M. reza. (2021). Magnesium removal from pregnant solution of acid leaching of zinc oxidised ore. Journal of Separation Science and Engineering, 13(1), 124–131. https://doi.org/10.22103/
jsse.2021.3001
[18] Sharma, K. D. (1990). An approach to reduce magnesium from zinc electrolyte with recovery of zinc from disposed residue of an effluent treatment plant. Hydrometallurgy, 24(3), 407–415. https://doi.org/10.1016/0304-386X(90)90102-8, Voigtm, P. B. (2012). Precipitation of zinc from solution.