No abstract

No abstract

Dielectric permittivity and loss tangent were measured on: 1) pressed disks of four different calcium aluminate cements shear mixed with water and poly(vinyl alcohol) and cured at room temperature and 2) laminates of SECAR 71 cement sintered at 1450°C. Post resonance and perturbation methods were used for microwave frequency measurements. Far infrared dielectric response of the cements was determined by FTIR in the diffuse reflectance mode. The real and imaginary parts of the relative dielectric permittivity were obtained via a conventional Kramers-Kronig analysis.

No abstract

High alumina radioactive waste calcine is produced at the Idaho Chemical Processing Plant (ICPP) by feeding a taw liquid waste stream through a fluidized bed calcitter. Further solidification of this calcine via chemical bonding necessitates determination of the amount of crystalline phase resulting from the calcination process. X-ray powder diffraction analysis of simulated (non-radioactive) ICPP high alumina calcine shows that it consists of an amorphous phase plus three phases of varying crystal Unity; alpha, beta and gamma alumina. Subsequent quantitative x-ray analysis of the three crystalline phases was carried out using the internal standard method with sodalite as the standard phase. Limited peak selection for the alumina phases required a correction for the presence of a small sodalite peak contained within the analyzed gamma alumina peak (4° two-theta base width). Results of this study show that the calcine is composed of ∼90 weight percent gamma alumina, less than 3-4 weight percent each of alpha and beta alumina and the remaining 4-6 weight percent an amorphous component.