Process technology — rare and refractory metals

Abstract

India has fairly rich reserves of rare and refractory metals. Abundant sources of ilmenite, rutile, zircon and rare earths are found in the placer deposits of the southern and eastern coasts of the country. Columbite-tantalite occur in mica and the mining belts of Bihar and cassiterite deposits are found in Bastar (Madhya Pradesh). Vanadium as a minor associate occurs in bauxites and in the vast deposits of titaniferrous magnetites.

Over the years, research and development and pilot plant works in many research organisations in India have built up a sound technological base in the country for process metallurgy of many refractory and rare earth metals starting from their indigenous sources. The present paper provides a comprehensive view of the developments that have taken place till now on the processing of various refractory and rare earth metals with particular reference to the extensive work carried out at the Department of Atomic Energy. The coverage includes mineral beneficiation, separation of individual elements, preparation of pure intermediates, techniques of reduction to metal and final purification. The paper also reviews some of the recent developments that have been taken place in these fields and the potential application of these metals in the foreseeable future.