Unlike Distillation, the extraction procedure has some disadvantages regarding the addition of a new solvent component that may cause in additional impurities due to incomplete immiscibility. Extraction is a material separation process in which any component is selectively and exclusively separated from a solid-liquid multi-component mixture. In this book, theory, design and applications are described in details. This book will be helpful for the students aspiring to gather knowledge in the field of chemistry, environmental science and chemical engineering.