Prethodno priopćenje
EFFECT OF DIFFERENT MODIFIERS ON MELTING POINTS, PH UNDER LEACHING AND LEACHING RATES IN SIMULATED NUCLEAR WASTE GLASSES IN BOROSILICATE AND PHOSPHATE SYSTEMS
Goutam Hazra
orcid.org/0000-0003-1908-3347
; Department of Chemistry, Kalna College, Kalna, Burdwan, India
Patit Paban Malik
; Department of Chemistry, B. B. College, Asansol, Burdwan, India
Partha Mitra
; Department of Physics, The University of Burdwan, Burdwan, India
Tanmoy Das
; Department of Chemistry, The University of Burdwan, Burdwan, India
Sažetak
Glasses were melted in the Borosilicate, Phosphate and Pure silicate systems. In the present work we could melt the glass at much lower temperature (800-950oC) with a soaking period of 30 min to 1 h which were earlier reported to be melted not below 1000oC. Considering that the glass will be utilized to incorporate nuclear waste with some of the fission products which are highly volatile, the lower the glass processing temperatures the better will be the glass melt. Leaching studies of nuclear waste glasses are important from the view point that they are to be stored for very long period under burial. The effect of different modifier ions like: Pb2+, Ba2+, Na+, Fe3+, Al3+, Y3+, Ca2+, Ce4+ and Sr2+ in each of the basic glass system viz, borosilicate and phosphate networks on meltings and time of melting has been found to be evident. The pH determination ranging from 6.43 up to 8.18 of the leachate solution at ambient temperature under varying time intervals shows interesting and regular variations. The results are in conformity with the change of equilibrium pH under varying leaching time reported by other authors. The leaching study of such glasses under Soxhlet condition shows that lead ion (Pb2+) to be a superior candidate as modifier towards leach resistance. The findings have been corroborated in terms of ionic size, ionic radii and hence ionic potential of the modifier ions incorporated into the glass structure.
Ključne riječi
nuclear waste; fission fragments; glass formers and modifiers; ionic potential; leaching
Hrčak ID:
128737
URI
Datum izdavanja:
12.10.2014.
Posjeta: 834 *