Synthesis and long-term test of borosilicate-based sealing glass for solid oxide fuel cells

2014

Vitrification is the most effective method of the hazardous waste immobilization. Toxic elements are incorporated into glass structure. Iron phosphate glasses are presently being considered as a matrix for storage of the radioactive waste which cannot be vitrified using a conventional borosilicate glass. Influence of Na 2 SO 4 as one of the components such the waste on thermal properties and crystallization ability of iron phosphate waste glass was studied. It was observed that Na 2 SO 4 decreases transformation temperature and increases DC p . The glass characteristic temperatures, glass crystallization ability, and crystallizing phases were determined. Na 2 SO 4 increases the glass crystallization ability which could be related with DC p heat capacity accompanying glass transition changes. The glass internal structure rebuilding, accompanying the sodium content increase, is considered. It is shown that DC p is a suitable, structure-sensitive glass crystallization ability, parameter.

Section: Resultsmentioning

confidence: 82%

Thermal properties of phosphate glasses for salt waste immobilization

2014

“…All of the investigated glasses evidenced a quite good thermal stability comparable with conventional silicate glasses for which K H value varied from 0.14 to about 1.3 [16,[27][28][29][30]. The increasing Na 2 SO 4 addition causes decrease in the K H parameter which means lowering the glass stability against crystallization and at the same ability of glass to vitrify on cooling [30].…”

Section: Dsc Analysis Of the Glassesmentioning

confidence: 79%

Thermal properties of 60P2O5–20Fe2O3–20Al2O3 glass for salt waste immobilization

et al. 2015

Vitrification is the most effective method of hazardous waste immobilization. Toxic elements are incorporated into a glass structure. Iron alumino-phosphate glasses are presently being considered as a matrix for storage of a radioactive waste which cannot be vitrified using conventional borosilicate waste glasses. Influence of Na 2 SO 4 as a one of components such the waste on thermal properties and crystallization ability of 60P 2 O 5 -20Fe 2 O 3 -20Al 2 O 3 glass was studied. It was observed that Na 2 SO 4 decreases transformation temperature and increases DC p . The glass characteristic temperatures, glass crystallization ability and crystallizing phases were determined. Na 2 SO 4 increases the glass crystallization ability which could be related with DC p heat capacity accompanying glass transition changes. The glass internal structure rebuilding accompanying the sodium content increase is considered. The obtained results were compared with structural model previously developed for 60P 2 O 5 -40Fe 2 O 3 glass and showed the structural similarity between these glasses.

“…The values of K H parameters for silicate glasses varied from 0.14 to about 1.3 [12][13][14]. The increasing of the ash concentration is causing decrease of the K H parameter and thus it lowers the glass stability against crystallization on heating and in the same way the glass ability to vitrify on cooling [14].…”

Section: Resultsmentioning

confidence: 99%

Thermal properties of vitrified llw hospital waste incineration ash

2013

The low level nuclear waste (LLW) resulting from the use of radioactive isotopes in medicine, industry, laboratories, and other purposes can be immobilized by vitrification, using methods applied in the nuclear power industry. Borosilicate glass is providing the very suitable medium for the majority of the species present in these wastes. Management of LLW waste begins with combustion reducing their amount. The paper presents the results of model studies of vitrification of hospital waste by incorporating it into the composition of boro-aluminosilicate glass, similar to those used in nuclear power industry. The proposed borosilicate waste glass composition was: SiO 2 -56.0, B 2 O 3 -15.0, Na 2 O-21.0, and Al 2 O 3 -8.0 (mass %). The ashes were mixed in different amount with the glass frit and then remelted to obtain homogenous melt which was vitrified. The influence of the main ash components on the thermal properties of the vitrified waste was studied using DSC and heating microscopy methods. The glass transformation, crystallization and melting temperatures, and Hruby glass stability against crystallization parameter were determined. The correlations between DC p , T g, and K H were observed and discussed.