Extractive metallurgy is that branch of metallurgy that deals with ores as raw material and metals as finished products. It is an ancient art that has been transformed into a modem science as a result of developments in chemistry and chemical engineering. The present volume is a collective work of a number of authors in which metals, their history', properties, extraction technology, and most important inorganic compounds and toxicology are systematically described.

Without reagents there would be no flotation, and without flotation the mining industry, as we know it today, would not exist. Reagents in mineral processing are therefore an inseparable part of the flotation process. Many books, articles and patents exist on development of reagents, reagent chemistry and reagent application.

In the past several decades considerable emphasis was placed on investigation of flotation properties of industrial minerals. The interest in process development for beneficiation of various industrial minerals also comes from the growing need to recover economic minerals from lower grade ores. In general terms these ores in which the minerals exist as ores are associated with, complex, silicates do not respond to the concentration methods used to treat higher-grade less complex mineral silicate ores.