Effect of V₂O₅ on crystallization tendency and chemical durability of Mo-bearing aluminoborosilicate glass

Abstract

AbstactThe effect of V 2 O 5 addition on molybdates crystallization tendency, glass structure and chemical durability of aluminoborosilicate glass belonging to SiO 2 -B 2 O 3 -CaO-Na 2 O-Al 2 O 3 -MoO 3 system has been studied. The results confirm that V 2 O 5 addition can effectively suppress the crystallization tendency of powellite and enhance the molybdenum solubility in the glass. The MoO 3 solubility limit is found to be 2.8 mol% in the V 2 O 5 -containing aluminoborosilicate glass. Raman results reveal that V 2 O 5 addition seems to modify the local structural environment of isolated MoO 4 units and increase their chemical disorder in the glass, which is favored for molybdenum incorporation in the glass. The molar volume and glass transition temperature of samples are found to depend on V 2 O 5 content. Product consistency test (PCT) results show that the normalized leaching rates of the V 2 O 5 -containing aluminoborosilicate glass maintain at a fairly low level compared with standard borosilicate glassy waste form.

Effect of Li2O substitution for Na2O on the solubility and water durability of Mo in aluminoborosilicate glass

“…On the basis of experimental structural data 16,17 ten system components were considered in the ZnO-Nb The molar Gibbs energies of Z, Nb, P, and Z3P were taken from the FACT database. 20,21 The unknown molar Gibbs ( 1 )…”

“…These studies include the addition of an appropriate amount of rare earth elements (Nd and La) or high-field ions (Mg) in borosilicate glass. 6,7,11,15,16 According to the previous literature, high field strength cations contribute to the formation of aluminum at 5 coordination ( [5] Al) and aluminum at 6 coordination ( [6] Al) in borosilicate aluminum glass. 17,18 When Al 3+ ions are at 6 or 5 coordination positions, they are considered to enter the depolymerization regions as network modifiers, 19 which further affects the solubility of Mo in borosilicate glass.…”

“…More details can be found in. 16,17 Raman spectra were multiplied by a constant, thus the maximum value of spectral intensity equals to one.…”

“…13 niobyl(3+) cation (NbO 3+ ), which enters deform dra (octahedra, tetragonal pyramids) with a co covalent bond to oxygen. 16,17 2 | METHOD 2.1 | Thermodynamic model of…”

“…17,18,27 Therefore, the substitution of Li + for Na + with low field strength promotes the T A B L E 3 The percentage of [3] B, [4] B, [4] Al, [5] Al, and [6] Al obtained from Gaussian fitting and the Gaussian fitting errors niobyl(3+) cation (NbO 3+ ), which enters deformed polyhedra (octahedra, tetragonal pyramids) with a coordinationcovalent bond to oxygen. 16…”