Treatise on Process Metallurgy, Volume 2B: Unit Processes, presents various unit processes with an emphasis on mineral processing, hydrometallurgy, and electrochemical materials and energy processes. The book highlights the roles of these processes in beneficiation, rare-earth extraction, utilization of lean resources, coal extraction, and biofuels, reflecting the shift toward green and electrochemical processes. Basic knowledge of thermodynamics and kinetics is provided for better understanding of metallurgical processes. The first section of the book covers mineral processing, providing insight on comminution, separation processes, dewatering, and tailings disposal. The second section focuses on hydrometallurgy, discussing leaching, separation-purification, metal recovery, and battery materials, and the book concludes with a section studying electrochemical material and energy, featuring coverage of molten oxide electrolysis, molten carbonate fuel cells, various sensors, and ionic liquids. Each section also includes various case studies, demonstrating the use of the concepts in real-world settings.