Since 1939, the U.S. government, using the National Defense Stockpile (NDS), has been stockpiling critical strategic materials for national defense. The economic and national security environments, however, have changed significantly from the time the NDS was created. Current threats are more varied, production and processing of key materials is more globally dispersed, the global competition for raw materials is increasing, the U.S. military is more dependent on civilian industry, and industry depends far more on just-in-time inventory control. To help determine the significance of these changes for the strategic materials stockpile, the Department of Defense asked the NRC to assess the continuing need for and value of the NDS. This report begins with the historical context of the NDS. It then presents a discussion of raw-materials and minerals supply, an examination of changing defense planning and materials needs, an analysis of modern tools used to manage materials supply chains, and an assessment of current operational practices of the NDS.

The growth and development witnessed today in modern science, engineering, and technology owes a heavy debt to the rare, refractory, and reactive metals group, of which niobium is a member. Extractive Metallurgy of Niobium presents a vivid account of the metal through its comprehensive discussions of properties and applications, resources and resource processing, chemical processing and compound preparation, metal extraction, and refining and consolidation. Typical flow sheets adopted in some leading niobium-producing countries for the beneficiation of various niobium sources are presented, and various chemical processes for producing pure forms of niobium intermediates such as chloride, fluoride, and oxide are discussed. The book also explains how to liberate the metal from its intermediates and describes the physico-chemical principles involved. It is an excellent reference for chemical metallurgists, hydrometallurgists, extraction and process metallurgists, and minerals processors. It is also valuable to a wide variety of scientists, engineers, technologists, and students interested in the topic.

Rare Earth Elements (REE) as well as tantalum and niobium are of tremendous importance because of their specific high-technology applications. The contributions gathered in this volume give an up-to-date survey on the mineralogy, primary ore deposits, prospecting, processing and applications of REE, Ta, and Nd, making this volume a useful handbook for practitioners and students. Finally, the comprehensive coverage of the fundamental aspects, especially as regards REE as tracers of geological phenomena, will prove extremely helpful.

Scientific notes and summaries of investigations in geology, hydrology, and related fields.