The book attempts to present a comprehensive view of Extractive Metallurgy, especially Principles of Extractive Metallurgy in a concise form. This is the first book in this area which attempts to do it. It has been written in textbook style. It presents the various concepts step by step, shows their importance, deals with elementary quantitative formulations, and illustrates thorough quantitative and qualitative information. The approach is such that even undergraduate students would be able to follow the topics without much difficulty and without much of a background in specialized subjects. This is considered to be a very useful approach in this area of technology. Moreover the inter-disciplinary nature of the subject has been duly brought out. While teaching concerned course(s) in the undergraduate and postgraduate level the authors felt the need of such a book. The authors found the books available on the subject did not fulfill the requirements. No other book was concerned with all relevant concepts. Most of them laid emphasis either on thermodynamic aspects or on discussing unit processes. Transport phenomena are dealt with in entirely different books. Reactor concepts were again lying in chemical engineering texts. The authors tried to harmonize and synthesize the concepts in elementary terms for metallurgists.The present book contains a brief descriptive summary of some important metallurgical unit processes. Subsequently it discusses not only physical chemistry of metallurgical reactions and processes but also rate phenomena including heat and mass transfer, fluid flow, mass and energy balance, and elements of reactor engineering. A variety of scientific and engineering aspects of unit processes have been discussed with stress on the basic principles all throughout. There is an attempt to introduce, as much as possible, quantitative treatments and engineering estimates.