Vaporization of alkali borosilicate glasses

Asano, Masaharu; Kou, Tomoyuki; Mizutani, Youichi

doi:10.1016/0022-3093(89)90558-9

Cited by 11 publications

(7 citation statements)

References 3 publications

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“…11 B MAS NMR measurements of the medium-range order reedmergnerite and danburite structures present in all compositions, confirm that volatility is more pronounced in aluminium oxide-and lanthanum oxide-containing glasses, where there is an increasing presence of danburite units, containing energetically less favorable B 4 -B 4 bonds and this is confirmed by volatilization measurements on caesium-containing danburite and reedmergnerite glasses. The composition of the volatile species was found to be of a mixed-alkali borosilicate form, whereas previous results in similar studies have found it to be alkali borate [7][8][9][10].…”

Section: Discussioncontrasting

confidence: 69%

“…8) show the volatile species to contain caesium, sodium, boron, silicon and probably lithium, suggesting the composition to be mixed-alkali borosilicate in form. The studies carried out by Asano et al [7,9,10] and Bonnell et al [8] on vaporization from caesium-containing borosilicate glasses, found the composition of the vapour to be alkali borate in form, devoid of any silicon.…”

Section: Nmr and Volatilization Measurementsmentioning

confidence: 97%

“…A significant problem associated with the process of HLW vitrification is the evolution of a volatile species at the glass melt stage. Although the volatile species is known to be caesium-containing [6][7][8][9][10], its overall composition and the structural conditions affecting its formation have still to be fully established. We have sought to identify those structural changes which occur in the solid glass when caesium oxide is added to a variety of simulated waste-forms and attempt to relate these to the measured volatilization losses from the melt.…”

Section: Introductionmentioning

confidence: 99%

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Effect of minor additions on structure and volatilization loss in simulated nuclear borosilicate glasses

Parkinson

Holland

Smith

et al. 2007

Journal of Non-Crystalline Solids

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Section: Discussioncontrasting

confidence: 69%

Section: Nmr and Volatilization Measurementsmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

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Effect of minor additions on structure and volatilization loss in simulated nuclear borosilicate glasses

Parkinson

Holland

Smith

et al. 2007

Journal of Non-Crystalline Solids

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“…Boron is one of the volatile elements during melting at high temperature. 4 The analytical results on the reference material of glass (NIST SRM1412) using the same method (Table 3) implied a slight effect of volatilization of B, i.e. the deviation of analytical value of B from certified value for the reference material of glass was negative.…”

Section: Analytical Results Of the Wvp-waste Glassmentioning

confidence: 95%

Chemical Analysis of High-Level Radioactive Waste Glass by ICP-AES

Banba¹,

Hagiya²,

Tamura³

et al. 1998

ANAL. SCI.

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In a reprocessing plant for spent nuclear reactor fuel, the spent fuel is dissolved in concentrated nitric acid solution, and plutonium and unburned uranium are removed in the chemical separation process. The remaining solution contains more than 99% of the nonvolatile fission product elements, impurities from the cladding materials, corrosion products, traces of unseparated plutonium and most of the transuranic elements. This reprocessing waste is called high-level radioactive liquid waste (HLLW). The HLLW is generally concentrated by evaporation and stored as an aqueous nitric acid solution in high-integrity stainless-steel tanks. Internationally, glass is the material of choice for incorporating and immobilizing the hazardous radionuclides in HLLW because of the good product durability and technical maturity. Recently, the HLLW arising from the commercial reprocessing plants were converted into borosilicate glasses in the vitrification plants in France (in the R7 and T7 Vitrification Plants at La Hague), and in the UK (in the Windscale Vitrification Plant (WVP) at Sellafield).1 Part of the vitrified products produced at La Hague have been already returned to Japan and the products vitrified at Sellafield will be returned to Japan in the near future, according to the agreements between the Japanese electric power companies and Compagnie Generale des Matieres Nucleaires (COGE-MA) or British Nuclear Fuels plc (BNFL) for the reprocessing of irradiated oxide fuel. In these situations, it is necessary to confirm the general characteristics of these vitrified products. At the Japan Atomic Energy Research Institute (JAERI), a series of characterization tests (chemical analysis, heat load measurement, leaching test, homogeneity and devitrification test) on the radioactive samples of vitrified residues were performed in cooperation with Commissariat a l'Energie Atomique (CEA), COGEMA and BNFL with the support of Science and Technology Agency (STA). 2The chemical analysis of the vitrified products produced in the industrial vitrification plant is one of the most important subjects in the characterization tests, because the analytical data are effective for the confirmation of the agreement between the industrial product and designed product. However, the chemical analysis of industrial vitrified product has never been carried out in other countries. In our previous study, an analytical method was developed and evaluated by using inactive samples for supporting the characterization tests of actual high-level radioactive waste glass. 3 The good accuracy of the method was demonstrated by the analytical data of the simulated inactive waste glass sample and several reference materials of glasses (National Institute of Standards and Technology: NIST SRM). Thereafter, this analytical method was modified slightly from the standpoints of the remote sample preparation in the shielded cells (e.g. use of devices and equipment protected from breaking) and the improvement of ICP-AES (e.g. determination of Li and Na by the addition of...

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“…The analytic data show that the aerosol concentration in the exhaust gases and the rate of absolute loss of mass increase sharply when sludge with a higher water content is loaded, i.e., the high losses of the components are due to is not so much the high temperature of the process as the aerosol removal of the components with the vapor-gas flow. Together with the high volatility of boric acid with water vapor, boron losses are also due to the evaporation of alkali borates at high temperature [7]. The sodium and iron losses could also be due in part to the volatility of their chlorides [8,9].…”

mentioning

confidence: 99%

Vitrification of a high-level iron-aluminate wastes simulator in a cold crucible

Kobelev¹,

Stefanovksii²,

Лебедев³

et al. 2010

At Energy

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An increase of the water content of a simulator of sludges from the test area at the Savannah River Plant (USA) which are vitrified in a cold crucible with inner diameter 236 mm from 50 to 70 wt % results in a substantial reduction of the mass loading rate of the sludge, production of molten glass, and specific production of the glass product. The specific energy expenditures on vitrification increase by more than a factor of 2. The formation of an undesirable nepheline phase is observed in samples containing more than 60 wt % wastes simulator. The chemical stability of the glass product remains high even when its wastessimulator content is 65 wt %.Vitrification is being studied in the USA as the main method of reprocessing liquid radioactive wastes, specifically, high-level wastes from a site in Savannah River (USA) [1]. Part of such wastes, for example, SB4 pulp, contains highly concentrated sodium, aluminum, and iron. One negative aspect of vitrification is the formation of nepheline, which depletes the matrix glass phase of aluminum and silicon and, in consequence, lowers the chemical resistance of the glass product [2]. The present work is a continuation of studies of the possibility of vitrifying high-level wastes which contain a high concentration of aluminum and iron by the method of induction melting in a cold crucible [3][4][5]. The objective of the present work is to determine the maximum content of wastes in the glass product that does not result in the precipitation of appreciable quantities of nepheline and the technological parameters of the melting in a crucible during the vitrification of a simulator of highlevel wastes.The experiments were performed in a cold crucible, whose inner diameter and height are 236 mm and 520 mm, respectively, in a stand facility [3]. A portion of the wastes simulator in the form of pulp (P1) was prepared using a procedure developed at the Savannah River National Laboratory, where manganese dioxide and iron and nickel hydroxides are precipitated and then a solution of sodium hydroxide and nitrate with pH 10.5 is added followed by the remaining components of the wastes [6], and another portion (P2) was prepared from reagents by a simplified method as described in [5]. In all, four charges in the form of sludge were prepared from the wastes simulators and 503-R4 frit with composition (wt %) B 2 O 3 16, Li 2 O 8, SiO 2 76, calculated for obtaining glass with 60 and 70 wt % high-level wastes simulator (Table 1). The sludges S1 and S3 were prepared from P2 pulp and frit; the sludges S2 and S4 were prepared from P1 pulp and frit with water content 50 and 70 wt %, respectively. .x-Ray phase analysis (DRON-4 diffractometer, FeK α radiation) shows that the phase composition of the charges does not depend on the method of preparation: the main components in all pre-dried charges are aluminum hydroxide Al(OH) 3 in the form of gibbsite and goethite FeOOH and sodium nitrate (nitratin) NaNO 3 . Negligible amounts of manganese and nickel oxides-hydroxides, thenardite (Na 2 SO 4 ), an...

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Vaporization of alkali borosilicate glasses

Cited by 11 publications

References 3 publications

Effect of minor additions on structure and volatilization loss in simulated nuclear borosilicate glasses

Effect of minor additions on structure and volatilization loss in simulated nuclear borosilicate glasses

Chemical Analysis of High-Level Radioactive Waste Glass by ICP-AES

Vitrification of a high-level iron-aluminate wastes simulator in a cold crucible

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