查看更多>>摘要：The history of human civilization is intimately interwoven with the history of utilization of materials. Sir George Thomson's remark - "the possibilities of a culture are limited by the materials at its disposal, though not every culture reaches the limits thus met" - very appropriately emphasises the crucial role that materials have played in the evolution of civilizations right from the dawn of the paleolithic age. Man's association with materials has been a rich and rewarding one, with diverse materials leaving their imprints, directly and indirectly on almost every facet of human endeavour, individual and collective.
查看更多>>摘要：The history of human civilization is intimately interwoven with the history of utilization of materials. Sir George Thomson's remark - "the possibilities of a culture are limited by the materials at its disposal, though not every culture reaches the limits thus met" - very appropriately emphasises the crucial role that materials have played in the evolution of civilizations right from the dawn of the paleolithic age. Man's association with materials has been a rich and rewarding one, with diverse materials leaving their imprints, directly and indirectly on almost every facet of human endeavour, individual and collective.
查看更多>>摘要：The zircon sands of India contain about 3 per cent hafnium expressed as Hf X 100/Hf + Zr. As a consequence of the very close similarity between the chemical behaviour of zirconium and hafnium, the problem of their separation is attended with unusual difficulties, although several methods have been proposed for this purpose from time to time. The recognition of the importance of hafnium-free zirconium as a structural and cladding material for reactor applications has accentuated interest in this problem during recent years.
查看更多>>摘要：The zircon sands of India contain about 3 per cent hafnium expressed as Hf X 100/Hf + Zr. As a consequence of the very close similarity between the chemical behaviour of zirconium and hafnium, the problem of their separation is attended with unusual difficulties, although several methods have been proposed for this purpose from time to time. The recognition of the importance of hafnium-free zirconium as a structural and cladding material for reactor applications has accentuated interest in this problem during recent years.
查看更多>>摘要：During the last thirty years the separation of hafnium from zirconium has been attempted by various methods, ranging from fractional crystallisation and fractional distillation to paper chromatography and even thermal diffusion. The emphasis on the chemical identity of the two elements, however, has always been so dominant that, until very recently, there was a tendency to exclude schemes of separation based on possible differences in chemical behaviour. Although zirconium and hafnium do show a very close correspondence in their chemical properties, a comparative study of their electronic structure and ionisation potentials, and an analysis of the available thermochemical data suggest that there should exist certain differences in stability between analogous compounds of these two elements, which may be purposefully exploited for their separation.
查看更多>>摘要：During the last thirty years the separation of hafnium from zirconium has been attempted by various methods, ranging from fractional crystallisation and fractional distillation to paper chromatography and even thermal diffusion. The emphasis on the chemical identity of the two elements, however, has always been so dominant that, until very recently, there was a tendency to exclude schemes of separation based on possible differences in chemical behaviour. Although zirconium and hafnium do show a very close correspondence in their chemical properties, a comparative study of their electronic structure and ionisation potentials, and an analysis of the available thermochemical data suggest that there should exist certain differences in stability between analogous compounds of these two elements, which may be purposefully exploited for their separation.
R. B. SubramanyamT. S. SitaramanC. S. Ramachandran
18页
查看更多>>摘要：Proven Indian reserves of ilmenite in the coastal beach-sands are one of the world's largest. Realizing the vast potential of titanium for a variety of end-use applications, (Late) Prof. C.V. Sundaram initiated a program on the extractive metallurgy of titanium in the early 1960s at the Bhabha Atomic Research Center, Mumbai (BARC) which went through several stages of development not only at BARC but also at the Nuclear Fuel Complex, Hyderabad (NFC) and finally culminated in the establishment of a Technology Development Center for Titanium at the Defence Metallurgical Research Laboratory, Hyderabad (DMRL) wherein large-scale trials were conducted and process conditions optimized for commercial scale production of titanium sponge in 3000 to 3500 Kg batches. Based on this technology, a 500 TPY capacity Titanium Sponge Plant is currently being set up by The Kerala Minerals and Metals Limited, Chavara (KMML). This Paper describes the various stages of development that have taken place during the last four decades or so in the indigenous efforts of technology development, which the authors believe will be a fitting tribute to (Late) Prof. C.V. Sundaram under whose inspiring leadership and guidance the entire program was conceived and developed leading up to the present stage of technology transfer.
R. B. SubramanyamT. S. SitaramanC. S. Ramachandran
18页
查看更多>>摘要：Proven Indian reserves of ilmenite in the coastal beach-sands are one of the world's largest. Realizing the vast potential of titanium for a variety of end-use applications, (Late) Prof. C.V. Sundaram initiated a program on the extractive metallurgy of titanium in the early 1960s at the Bhabha Atomic Research Center, Mumbai (BARC) which went through several stages of development not only at BARC but also at the Nuclear Fuel Complex, Hyderabad (NFC) and finally culminated in the establishment of a Technology Development Center for Titanium at the Defence Metallurgical Research Laboratory, Hyderabad (DMRL) wherein large-scale trials were conducted and process conditions optimized for commercial scale production of titanium sponge in 3000 to 3500 Kg batches. Based on this technology, a 500 TPY capacity Titanium Sponge Plant is currently being set up by The Kerala Minerals and Metals Limited, Chavara (KMML). This Paper describes the various stages of development that have taken place during the last four decades or so in the indigenous efforts of technology development, which the authors believe will be a fitting tribute to (Late) Prof. C.V. Sundaram under whose inspiring leadership and guidance the entire program was conceived and developed leading up to the present stage of technology transfer.
查看更多>>摘要：The paper describes the evolution and development of analytical methods for high purity zirconium sponge and quality control programme for the Indian production programme of nuclear grade zirconium sponge. Some typical production problems tackled by applying analytical procedures are also discussed.
查看更多>>摘要：The paper describes the evolution and development of analytical methods for high purity zirconium sponge and quality control programme for the Indian production programme of nuclear grade zirconium sponge. Some typical production problems tackled by applying analytical procedures are also discussed.
NSTL