ALEJANDRO LÓPEZ VALDIVIESO (1953-2024)

BY KENNETH N. HAN AND
JAMES E. GEBHARDT
(with contributions from Aurora Robledo Carrera)

ALEJANDRO LÓPEZ VALDIVIESO died on Oct. 27, 2024. At the time of his death, Alejandro was a professor of minerals engineering in the Department of the Institute of Metallurgy at the University of Autónoma de San Luis Potosi (UASLP) in San Luis Potosi, Mexico. He remained active in both teaching and research until the onset of his final illness. Alejandro was born on Aug. 18, 1953, in Juchitáan, Mexico, to Heriberto López and Minerva Valdivieso. He was one of five siblings.

His impressive professional career, spanning nearly five decades, began with studies at the School of Chemical Engineering and Extractive Industries of the National Polytechnic Institute, where he earned a degree in chemical metallurgical engineering in 1976. During his time there, he visited and studied numerous mining companies in Mexico — an experience that proved crucial in shaping his research interests. With a prestigious fellowship from the U.S. Bureau of Mines, Alejandro continued his education at the South Dakota School of Mines and Technology, earning a Master of Science degree in metallurgical engineering in 1980. He went on to pursue doctoral studies as a Jane Lewis Foundation Fellow at the University of California, Berkeley, where he earned his Ph.D. in materials science and mineral engineering in 1988. During these years, he remained engaged in academic activities in Mexico, including co-organizing a symposium on the flotation chemistry of mineral separations.

He began his career as a member of the academic staff in the Department of Metallurgy at ESIQIE-IPN from 1977 to 1980. On Dec. 1, 1988, he became a research professor at the Institute of Metallurgy of the UASLP, where he established himself as a leader in mineral processing and extractive metallurgy. Arriving with a clear vision for education in Mexico, particularly in a country with extensive mining activity, he promoted educational programs designed to train highly specialized professionals. In 2000, he collaborated in creating the Master of Science program in chemical engineering at the Faculty of Chemical Sciences, as well as the master’s and doctoral programs in environmental sciences. At the same time, with Marcos Gustavo Monroy Fernández, he founded the mineral engineering graduate program to prepare engineers for the mining sector and establish a connection between education and industry — an unprecedented initiative in Mexico’s educational system at the time.

Through this vision and leadership, Alejandro helped secure collaborations with major mining companies, including Grupo México, Industrias Peñoles, Fresnillo PLC, Minera Autlán, Minera Río Tinto, and Minera Frisco. These companies sought him out to solve problems and optimize processes across operations throughout the country. Such collaborations expanded the Institute of Metallurgy’s extractive metallurgy infrastructure and provided opportunities for outstanding students who lacked financial resources. He was a strong advocate for accessible public education, working to reduce tuition costs and offering support for living expenses.

Through programs sponsored by Mexico’s Consejo Nacional de Ciencia y Tecnología (CONACYT) and other initiatives, he established ways to expand and strengthen existing research in extractive metallurgy. He brought in young specialists in electrometallurgy, hydrometallurgy, environmental remediation, crushing and grinding, environmental geomicrobiology, and mineral characterization. His work was characterized by the application of engineering science principles to improve mineral recovery from complex ores, including those that had undergone oxidation. As coordinator of the Graduate Program in Mineral Engineering, Alejandro invited distinguished international professors in mineral processing to present on topics such as the modeling and simulation of crushers, mills, and hydrocyclone classification. He also encouraged graduate students to take courses with leading professors in the field.

He advised more than 100 professional theses and trained 16 doctoral students, many of whom are now professors at universities in China and Mexico. Others have built careers in the industrial mining and metallurgical sectors. He also taught and advised 41 master’s students, most of whom now work in the industrial sector. His research led to the publication of 123 papers in international journals and the award of five patents for industrial processes.

In 2007, he was elected a member of the Mexican Academy of Sciences. His national honors also include the National Metallurgy Prize, awarded by the Association of Mining Engineers, Metallurgists, and Geologists of Mexico for contributions to technological development and human resource training for the mining and metallurgical industries. He was a member of the National System of Researchers (SNII) at Level III, the highest in the system and the only member with this level in the mining and metallurgical field. It is worth noting that he was the first professor-researcher from the Faculty of Engineering and the Ministry of the Interior to receive this distinction.

Alejandro also had an outstanding record of international engagement in North America, South America, and China. He served on the International Technical Committee at PROCEMIN in Chile and was an active member of the International Scientific Committee for the International Mineral Processing Congress in Chile. In 2014, he was invited to join the Scientific Committee of the Water Resources Center for Agriculture and Mining at the Universidad de Concepción, Chile. He also served on the editorial committee for GEOMIMET, the journal of the Association of Mining, Metallurgical and Geological Engineers of Mexico, as well as the International Journal of Mineral Processing. His highest recognition came with his election as an international member of the National Academy of Engineering. Only five individuals from Mexico have received this honor, and he was the first from a public university to achieve it.

His seminal contributions to introducing the mineral processing program into the Mineral Engineering Program at UASLP helped make it one of the most prestigious in Mexico. The Mexican mining industry also benefited from his expertise, particularly his extensive knowledge of interfacial phenomena and the hydrometallurgical treatment of complex ores. In 2003, he was honored with the State Science and Technology Development Award, one of the most prestigious recognitions given to a scientist in Mexico. He worked with many mining companies in Mexico to introduce special depressants for fine particle recovery, innovative flotation technology and reactor design, and economically viable leaching technology to recover metals from challenging ores — such as those of copper, lead, zinc, and silver — from oxidized and finely disseminated minerals. Companies that benefited from his innovations included Minera Rio Tinto, S.A., Grupo Vitro, S.A., AMTEX S.A. (Mexico), Bilbao Minerals, Consorcio Minero Benito, and many others.

Alongside his significant contributions to education and research, Alejandro exemplified remarkable cultural inclusivity. His appreciation for diversity was reflected in his love for exploring and savoring a wide range of cuisines, and in his fluency in his native language as well as English and Spanish. He was proud of his indigenous Zapotec heritage, and this deep connection drove his dedication to fostering inclusive and diverse educational environments. An avid soccer enthusiast, he often brought friends and students together on the soccer field, playing enthusiastically, earning admiration, and serving as an inspiring role model.

Alejandro will be remembered as a consummate educator, world-renowned researcher, and dedicated professional and public servant. He inspired thousands of students to pursue excellence in their lives and careers. To those who knew and worked with him, he is remembered as a caring, considerate, patient, and kind person — genuinely enthusiastic and with a delightful personality. His family, friends, and many professional colleagues deeply miss him.

He was preceded in death by his wife, Bernada, and is survived by his three daughters, Biaani, Alejandra, and Andrea, and his life partner, Laura.