Oxidative acid leaching of mechanically activated sphalerite

ABSTRACT

The pressure leaching kinetics of mechanically activated sphalerite was investigated in this work. X-ray diffraction and scanning electron microscopy were used to characterise the influences of crystalline structure and morphology, respectively. A laser particle size analyser and specific surface area tester were used to determine the particle size and specific surface area, respectively. Compared to the non-activated sample, the activated samples demonstrated distinct physicochemical properties with higher reaction efficiencies and increased Zn recovery ratios. The activation energy of sphalerite decreased from 69.96 to 45.91, 45.11, and 44.44 kJ mol⁻¹ as the activation time increased from 0 to 30, 60, and 120 min, respectively. The reaction orders for the H₂SO₄ solutions of the sphalerite samples activated for 0, 30, 60, and 120 min were 1.832, 1.247, 1.214, and 1.085, respectively, which indicated that the dependency of the sphalerite leaching process on H₂SO₄ could be reduced by means of mechanical activation.

RÉSUMÉ

Dans ce travail, on a examiné la cinétique de lixiviation sous pression de la fausse galène activée mécaniquement. On a utilisé la diffraction des rayons x et la microscopie électronique à balayage pour caractériser l’influence de la structure cristalline et de la morphologie, respectivement. On a utilisé un analyseur de granulométrie au laser et un appareil pour la mesure de la surface massique afin de déterminer la taille de particule et la surface massique, respectivement. Par rapport à l’échantillon non activé, les échantillons activés ont démontré des propriétés physicochimiques distinctes, avec une efficacité de réaction plus élevée et une augmentation des pourcentages de récupération du zinc. L’énergie d’activation de la fausse galène diminuait, de 69.96 à 45.91, à 45.11, et à 44.44 kJ/mol à mesure que la durée d’activation augmentait de 0 à 30, à 60, et à 120 min, respectivement. L’ordre de la réaction des solutions d’H₂SO₄ des échantillons de fausse galène activés pendant 0, 30, 60, et 120 min était de 1.832, 1.247, 1.214, et 1.085, respectivement. Ceci indiquait qu’on pourrait réduire la dépendance du procédé de lixiviation de la fausse galène sur l’H₂SO₄, au moyen de l’activation mécanique.

KEYWORDS:

• Sphalerite
• Zn extraction
• mechanical activation
• leaching kinetics
• activation energy
• reaction orders

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

L. Tian is a lecturer at Jiangxi University of Science and Technology, China. His research interests include the hydrometallurgy and secondary resource recycling.

T. A. Zhang is a full professor of Northeastern University (NEU), China. He obtained Ph.D in Thermal Engineering from NEU. He served a ten-year term as head of School of Metallurgy at NEU. He has published more than 300 scientific papers and hold 62 technical patents for his many innovations. His primary research interests include alumina production, harmless utilisation of Bayer red mud and fly ash, new extraction process for V from vanadium containing slag, pressurised hydrometallurgy, and so on.

Y. Liu is a full professor of NEU, China. She obtained Ph.D in Thermal Engineering from NEU. She has published more than 50 scientific papers; 60 technical patents are authored. Her primary research interests include the reactor design and the reactor physics and mathematics simulation.

G. Z. Lv is an associate professor in Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education in China School of Metallurgy in Northeastern University. He has published more than 70 scientific papers; 40 technical patents are authored. His primary research interests include harmless utilisation of Bayer red mud and fly ash, new extraction process for V from vanadium containing slag.

J. J. Tang is a PhD student at NEU, China.

ORCID

T. A. Zhang http://orcid.org/0000-0002-9934-4713

Additional information

Funding

This work has been supported by the joint funds of the National Natural Science Foundation of China (No. U1402271, 51504058, 51504059).