This is the heart of the text. Before you can understand how to extract copper or iron, you must understand the energetics of reactions. The book provides a rigorous refresher on the First and Second Laws of Thermodynamics, activity-composition relationships, and the construction of phase diagrams (specifically Ellingham diagrams, which are crucial for pyrometallurgy).
At the end of each chapter, Rosenqvist includes problems with no solutions. Seek out the "Solutions Manual" (rare, but sometimes shared alongside the PDF). If you cannot find it, work through them with a friend. principles of extractive metallurgy terkel rosenqvist pdf
Though lighter on hydro than pyro, Rosenqvist provides a solid foundation for: This is the heart of the text