This book, intended for advanced graduate students of metallurgy, explains what happens in the critical period between extractive metallurgy and solidification and subsequent processing. An important point the book stresses is that the principles are the same in the treatment of various different metals. Someone concerned with the purification of one metal may learn from results and experiences gained on other metals and alloys. The specifics of metals such as iron and steel, aluminium, and copper are discussed in examples and in problems at the end of each chapter. The book is self-contained and covers the basic thermodynamics and fluid mechanics required.