Zirconium and hafnium separation without waste generation.

Abstract The history of commercial processes for zirconium/hafnium production and separation is reviewed. A new technology is then proposed as a potential alternative for zirconium/hafnium separation in a simpler, cleaner way than achieved with current processes. Primary sources of zirconium always contain small amounts of hafnium that must be removed during production of zirconium metal for nuclear applications. This separation is usually carried out by a solvent extraction process, developed in the 1950s, that selectively extracts hafnium, as a thiocyanate complex, using methyl isobutyl ketone (MIBK). Environmental problems inherent to this process are the high aqueous solubility and low flash point of MIBK, and possible gaseous contaminants formation generated by the decomposition of the thiocyanic complexes in hydrochloric acid medium (H2S, HCN, mercaptanÕs formation). The present work shows how these problems could be avoided by using organophosphorous extractants that were unavailable when the MIBK process was developed.
Keywords: Environment, Zirconium, Hafnium, Separation technology.
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Summary: Many underground mining operations use Split Set friction stabilizer bolts for rock support. Currently, however, little has been done to quantify the effects of various rock mechanics and operational parameters on the capacity of frictional support systems. The strength of Split Sets is usually measured by means of a pull test wherein a jacking force is applied to the bolt and a slip load is obtained. In order to evolve a rational design procedure for this type of support, an extensive...
Publication: CIM Bulletin
Author(s): P.B. Tomory, M.W. Grabinsky, J.H. Curran, J. Carvalho
Keywords: Rock mechanics, Underground mining, Split Set friction stabilizer bolts, Friction bolts.
Issue: 1018
Volume: 91
Year: 1998
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