Kinetic model for quartz and spinel dissolution during melting of high-level-waste glass batch
The dissolution of quartz particles and the growth and dissolution of crystalline phases during the conversion of batch to glass potentially affects both the glass melting process and product quality. Crystals of spinel exiting the cold cap to molten glass below can be troublesome during the vitrification of iron-containing high-level wastes. To estimate the distribution of quartz and spinel fractions within the cold cap, we used kinetic models that relate fractions of these phases to temperature and heating rate. Fitting the model equations to data showed that the heating rate, apart from affecting quartz and spinel behavior directly, also affects them indirectly via concurrent processes, such as the formation and motion of bubbles. Because of these indirect effects, it was necessary to allow one kinetic parameter (the pre-exponential factor) to vary with the heating rate. The resulting kinetic equations are sufficiently simple for the detailed modeling of batch-to-glass conversion as it occurs in glass melters. The estimated fractions and sizes of quartz and spinel particles as they leave the cold cap, determined in this study, will provide the source terms needed for modeling the behavior of these solid particles within the flow of molten glass in the melter.
Cluster formation of silica particles in glass batches during melting
Abstract The study describes the incorporation of solid silica into molten glass during glass-batch melting as a function of the grain size in the range from 5 to 275 µm. Whereas tiny grains formed a bubbly melt, very large grains formed slowly dissolving clusters. Silica grains are forced to clusters by rising bubbles. The impact of the silica grain size on the glass-forming melt viscosity, overall density, thermal conductivity, and compositional homogeneity, as well as the consequences of these effects on glass processing in melting furnaces, is discussed. A high-alumina borosilicate glass for nuclear waste vitrification was chosen for the study, but the authors believe that the observed behaviors also occur in the melting of commercial batches.
2000 Review conference of the parties to the treaty on the non-proliferation of Nuclear Weapons, final document
4. The Conference notes that the non-nuclearweapon States Parties to the Treaty reaffirmed their commitment not to receive the transfer from any transferor whatsoever of nuclear weapons or other nuclear explosive devices or of control over such weapons or explosive devices directly, or indirectly, not to manufacture or otherwise acquire nuclear weapons or other nuclear explosive devices, and not to seek or receive any assistance in the manufacture of nuclear weapons or other nuclear explosive devices. 2000 REVIEW CONFERENCE OF THE PARTIES TO THE TREATY ON THE NON-PROLIFERATION OF NUCLEAR WEAPONS FINAL DOCUMENT