For two days from March 24 to March 25, 2023, the 16th Workshop on Reactive Metal Processing (RMW16) was held at the Massachusetts Institute of Technology (MIT). This annual international industry-academia collaborative workshop on reactive materials processing was jointly organized by Prof. Toru H. Okabe, Project Professor, and Prof. Shunsuke Yagi of the Institute of Industrial Science (IIS), the University of Tokyo, as well as Prof. Donald R. Sadoway and Prof. Antoine Allanore of MIT. This leading international workshop was attended by approximately
50 participants from countries including the USA, Canada, Norway, and Japan. RMW16 was held for the first time in three years after being suspended due to the COVID-19 pandemic. The two-day workshop included presentations on rare metals production, recycling, and processing, as well as advanced battery materials, which are essential for a sustainable society. Active and fruitful discussions were held among the participants, and the workshop contributed to the development of closer relations among the staff and students of MIT and the University of Tokyo.