02134nas a2200265   4500008004100000022001400041245010400055210006900159260007300228300001200301490000800313520113300321653006501454653003301519653002501552100002201577700002201599700001801621700001201639700001701651700002401668700003201692700001701724856012701741       2015                        eng d  a0022-311500aStudy on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents0 aStudy on fusedcast AZS refractories for deployment in vitrificat  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC  a144-1540 v4673 a<p>Fused/cast Al2O3-ZrO2-SiO2 (FC-AZS)' is being considered as `glass contact refractory' within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO2) within aluminosilicate (Al2SiO5) matrix. Al-27 and Si-29 NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO3, simulated wastes (500 h exposure), and borosilicate melt (975 degrees C, 800 h exposure) are found to be 0.38 x 10(3) mu my(-1), 0.13 x 10(3) mu my(-1) and 4.75 x 10(3) mu my(-1) respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al2O3-ZrO2-Cr2O3, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles. (C) 2015 Elsevier B.V. All rights reserved.</p>10aInteraction between refractory material and hazardous liquid10aNuclear waste immobilization10aVitrification melter1 aSengupta, Pranesh1 aMishra, Raman, K.1 aSoudamini, N.1 aSen, D.1 aMazumder, S.1 aKaushik, Chetan, P.1 aAjithkumar, Thalasseril, G.1 aBanerjee, K.  uhttps://library.ncl.res.in/content/study-fusedcast-azs-refractories-deployment-vitrification-radioactive-waste-effluents-002137nas a2200229   4500008004100000022001400041245003500055210003500090260006700125300001000192490000700202520145200209100002201661700002101683700001701704700003201721700001901753700002201772700002401794700002001818856006901838       2015                        eng d  a0002-782000aVanadium in borosilicate glass0 aVanadium in borosilicate glass  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcJAN  a88-960 v983 a<p>Understanding the role of V2O5 within borosilicate glass matrices is important for the development of novel matrices toward immobilization of sulfate containing high-level nuclear wastes. Present investigation shows, within sodium barium borosilicate glass matrix V2O5 can be homogeneously added up to 5mol% and beyond which it separates out into three phases, for example, (i) silica (ii) Barium (Ba) - Vanadium (V) oxide, and (iii) glass matrix. Si-29 MAS NMR (Nuclear Magnetic Resonance) studies of the samples show that below 5mol% V2O5 addition, silicate network is dominantly constituted of Q(2) and Q(3) structural units, whereas above this, the network gets more polymerized through formation of Q(3) and Q(4) units. In case of borate network, B-11 MAS NMR investigations revealed that the concentration of BO4 [(0B, 4Si)] unit increases gradually up to 5mol% and then it decreases at the cost of BO4 [(1B, 3Si)], BO3 (symmetric) and BO3 (asymmetric) units. Micro-Raman analyses of the samples showed that with additions of V2O5 in diluted concentrations, amorphous silicate network remained unaltered, whereas some amplification in signals corresponding to ring-type metaborate and VO5 units exists. It is therefore apparent from both MAS-NMR and micro-Raman studies that with V2O5 additions within the solubility limit (5mol%), borate network gets depolymerized leading to decrease in hardness from an average value of 5.0-4.2GPa.</p>1 aSengupta, Pranesh1 aDey, Krishna, K.1 aHalder, Rumu1 aAjithkumar, Thalasseril, G.1 aAbraham, Geogy1 aMishra, Raman, K.1 aKaushik, Chetan, P.1 aDey, Goutam, K.  uhttps://library.ncl.res.in/content/vanadium-borosilicate-glass-0