Ceramics-Silikáty 46, (1) 1 - 7 (2002) |
|
STRUCTURAL AND MECHANICAL RESPONSE TO A THERMO-RHEOLOGIC HISTORY OF SPINEL SLUDGE IN HIGH-LEVEL WASTE GLASS
|
Jiřička Miloš 1, Hrma Pavel 2
|
1 Laboratory of Inorganic Materials, Institute of Inorganic Chemistry ASCR and Institute of Chemical Technology, Prague,
Technická 5, 166 28 Prague, Czech Republic
2 Pacific Northwest National Laboratory, Richland, Washington 99352, U.S.A.
|
Keywords: Glass, Spinel, Rheology
|
The composition and structure of a sludge sample from a high-level waste glass melter were studied using optical and
scanning electron microscopy, and x-ray diffraction. At isothermal heat treatments between 1050°C and 1350°C, spinel
crystals partly dissolved to form on cooling tiny (~ 10 µm) star-like crystals or dendrites. The shear stress in sludge was
measured at a constant shear rate (from 0.005 s⁻¹ to 1.0 s⁻¹) and temperature (from 1050°C to 1350°C) during repeated
deformation and after idling. The initial thixotropic character of the loose structure of the settled sludge turned on subsequent
deformation (and idling) to rheopectic behavior. As the spinel concentration in the sludge decreased from 28 mass% (sludge
as received) to 15 mass% at 1300°C, the sludge turned into a Newtonian suspension. |
 PDF (0.2 MB) |
|
