12. Women in Hydrometallurgy

Women have made significant contributions to the development of hydrometallurgy, from the earliest scientific investigations of ore processing to modern innovations in extraction technologies. Some notable figures within hydrometallurgy include:

Marie Curie

Marie Curie’s research on radioactive minerals laid important foundations for chemical extraction and separation processes (Curie, 1898a; Curie, 1898b). While studying pitchblende, Curie observed that the ore exhibited greater radioactivity than could be explained by uranium alone, suggesting the presence of previously unknown radioactive elements (Curie, 1898a). Working alongside Pierre Curie, she processed large quantities of pitchblende residues using techniques that closely resemble modern hydrometallurgical operations, including acid leaching, dissolution, precipitation, selective chemical separation, and fractional crystallization (Curie, 1898a; Curie, 1898b). Through repeated chemical separations and radiometric measurements, the Curies identified radioactive fractions associated with bismuth and barium, leading to the discoveries of polonium and radium in 1898 (Curie, 1898a; Curie, 1898b). Their work required processing several tonnes of ore residues to isolate minute quantities of radium compounds and demonstrated the effectiveness of chemical extraction techniques for recovering valuable elements from complex mineral matrices (Curie, 1904).

Sehliselo (Selo) Ndlovu

One of the most influential contemporary hydrometallurgists is Sehliselo Ndlovu. Ndlovu’s research focuses on sustainable extraction of critical and precious metals from low-grade ores, mine wastes, acid mine drainage, and secondary resources. Her work spans leaching, bioleaching, solvent extraction, and flowsheet development for metals including copper, cobalt, rare earth elements, platinum group metals, and gold. She has emphasized the role of hydrometallurgy in building resilient critical mineral supply chains while reducing the environmental footprint of mining operations.

In her landmark paper, Biohydrometallurgy for Sustainable Development in the African Minerals Industry, Ndlovu argued that biohydrometallurgy had evolved from an emerging technology into an established and economically viable alternative for processing certain mineral resources, particularly sulfide ores. She highlighted the advantages of microbial-assisted leaching, including lower capital costs, operational simplicity, environmental compatibility, and suitability for treating low-grade ores that are often uneconomical using conventional extraction technologies (Ndlovu, 2008). Her work helped establish biohydrometallurgy as an important component of sustainable mineral development and demonstrated its potential for improving resource utilization in developing regions.

More recently, Ndlovu’s research program has expanded into the recovery of valuable metals from mine tailings, metallurgical wastes, and secondary resources, supporting circular economy principles within the mining industry(Kumar et al., 2025). By promoting the recovery of critical minerals from waste streams, her work demonstrates how hydrometallurgical technologies can simultaneously improve resource efficiency and reduce environmental impacts associated with mining and mineral processing.

Sepideh Javanshir

Sepideh Javanshir has made important contributions to the integration of bioleaching and solvent extraction technologies for the recovery of base and critical metals from low-grade ores and industrial residues. Her research has focused on improving the efficiency and selectivity of hydrometallurgical separation processes while reducing environmental impacts associated with conventional extraction methods. In a 2021 study, Javanshir and co-author Parastoo Tahmasebizadeh investigated the recovery of zinc from a bioleaching solution generated from a low-grade lead-zinc sulfide ore using modified di-(2-ethylhexyl) phosphoric acid (D2EHPA). Their work demonstrated that iron impurities could first be removed through jarosite precipitation before zinc was selectively extracted through solvent extraction. Under optimized conditions, zinc extraction efficiencies reached 98.4%, representing a significant improvement over conventional D2EHPA extraction systems. The study demonstrated how bioleaching and solvent extraction can be integrated into a single hydrometallurgical flowsheet for the treatment of low-grade ores and complex mineral resources (Tahmasebizadeh & Javanshir, 2021).

In a related study, Javanshir investigated the use of emulsion liquid membrane (ELM) technology for zinc recovery from bioleach liquors. The research optimized parameters such as extractant concentration, surfactant concentration, contact time, and stripping conditions, achieving zinc extraction efficiencies of approximately 71%. This work demonstrated the potential of membrane-based separation technologies as an alternative to conventional solvent extraction systems, offering improved selectivity and reduced reagent consumption in hydrometallurgical operations (Tahmasebizadeh, Javanshir, & Ahmadi, 2021).

Together, these studies highlight Javanshir’s contributions to sustainable metal recovery technologies and illustrate how modern hydrometallurgy is increasingly integrating biological extraction, solvent extraction, and advanced separation methods to improve the recovery of valuable metals from low-grade and secondary resources.

References:

• Curie, M., & Curie, P. (1898a). Sur une substance nouvelle radio-active contenue dans la pechblende (Polonium discovery).
• Curie, M., & Curie, P. (1898b). Sur une nouvelle substance fortement radio-active contenue dans la pechblende (Radium discovery).
• Curie, M. (1904). Recherches sur les substances radioactives.
• Ndlovu, S. (2008). Biohydrometallurgy for sustainable development in the African minerals industry. Hydrometallurgy, 91(1–4), 20–27.
• Kumar, A. et al. (2025). Bioleaching: from natural ores to urban mines for sustainability, circularity, and carbon neutrality.
• Tahmasebizadeh, P., & Javanshir, S. (2021). Solvent Extraction of Zinc from a Bioleaching Solution by Modification of D2EHPA: Optimization and Thermodynamic Studies. Journal of Mining and Environment, 12(1), 253–269.
• Tahmasebizadeh, P., Javanshir, S., & Ahmadi, A. (2021). Zinc Extraction from a Bioleaching Solution by Emulsion Liquid Membrane Technique. Separation and Purification Technology, 276, 119394.