Seshadri Seetharaman

Abstract:

Slags are by-products during the production of metals. Slags from alloy steelmaking often contain metal values. The slags pose a serious threat to nature when used in landfills. With suitable process development, the slags form very valuable secondary sources of these metals. A number of economically viable process routes have been developed during recent years in order to utilize the metal values in slags. An understanding of the physical chemistry of slags is necessary in order to enable this. Some of the unique measurements carried out in this direction will be presented in the planned lecture.
The new process solutions for the recovery of metals from slags consist of, among others, oxidation of slags containing Fe and Mn to produce nanoferrites and recovery of vanadium from vanadium sources including slags and low-grade ores by volatilization in oxidizing environments. A new patented salt-slag process, Salt Extraction Process, uses AlCl3 as flux in extracting the metal values into the slag phase. With simultaneous electrolysis, the metals are deposited at the cathode. The present approach has given rise to a number of applications in adjoining fields, such as extraction of Pb from CRT glass, extraction of rare-earths from scrap or low-grade sources as well as copper production from sulphide ores.
The synergetic effects of combining molten salts with slags are highlighted in the present talk.