This book is dedicated to the processes of mineral transformation, recycling and reclamation of metals, for the purpose of turning metals and alloys into a liquid state ready for pouring. Even though "process metallurgy" is one of the oldest technologies implemented by man, technological innovation, with the development of processes that are both focused on product quality and economically and ecologically efficient, continues to be at the heart of these industries. This book explains the physico-chemical bases of transformations, vital to their understanding and control (optimization of operational conditions), and the foundations in terms of "process engineering" (heat and matter assessment, process coupling: chemical reactions and transport phenomena), vital to the optimal execution and analysis of transformation process operations. This book is addressed to students in the field of metallurgy and to engineers facing the problem of metal and alloy development (operation of an industrial unit or development of a new process).