The rare elements

This book describes the technology of rare metals based on geology and geochemistry. A description is given of the main sources, enrichment of minerals and ores by gravitation, magnetic, electric, flotation and chlorination methods as well as the self-accumulation of rare elements in half-products and waste materials of the metallurgical industy. Because of their unusual properties, the rare elements are extracted by unconventional methods. Among them, the hydrometallurgical mehods which allow the isolation of groups of elements from the mixtures, followed by their precise separation. (author). refs.; tabs