This introduction presents an overview of the key concepts covered in the subsequent chapters of this book. The book discusses different types of mine waste generated and recovery thereof during the mining process right from the mineral extraction to the beneficiation and recovery processes to the manufacturing of finished products. Mineral beneficiation consists of manipulation of the physical properties of the ore to produce the desired particle sizes so as to liberate and concentrate valuable mineral from the gangue material. Acid Mine Drainage may be generated from mine waste rocks or mine structures such as active or closed or abandoned pits and underground workings. Hydrometallurgy is concerned with production of metals or metallic compounds from ores, concentrates or other intermediate materials by a sequence of operations carried out in aqueous solutions. Waste materials from the various metal value chain processes have the potential to act as a secondary value resource and/or utilized in a number of alternative industrial applications.