Researching about Removing Cadmium from Thallium-Bearing Materials with Vacuum Distillation

2011 ◽  
Vol 335-336 ◽  
pp. 1123-1136
Author(s):  
Shun Zhong Yao ◽  
Yong Nian Dai ◽  
Hao Huang

Abstract:Dealing with thallium-bearing materials by vacuum distillation under the condition of 400~700°Cand 10-60 Pa.Measured contents of Cd,Tl and Pb under these temperatures.Analzed relations between evaporation rate,residue duty of Cd with temperatures, and The relyations that between evaporation rate,evaporative duty of Tl and Pb with temperatures.Least square method is used to fit the relations and got that the most suitable temperature for evaporating Cd is 560°C;Analyzed the relations between the activity coefficients ratio of Cd-Tl system and Cd-Pb system and temperatures as well as mole fractions,also got fitted equations of them;Analyzed the relation between gas-liquid cotents of Cd-Tl,Cd-Pb systems and temperatures.It is valuable for extracting Tl,Pb with vacuum distillation.

2014 ◽  
Vol 50 (2) ◽  
pp. 171-176 ◽  
Author(s):  
K. Liu ◽  
J.J. Wu ◽  
W.H. Ma ◽  
B. Yang ◽  
X. Yang ◽  
...  

The vacuum distillation of aluminum from Si-Fe-Al ternary alloy with high content of Al is studied by a molecular interaction volume model (MIVM) in this paper. The vapor-liquid phase equilibrium of the Si-Fe-Al system in vacuum distillation has been calculated using only the properties of pure components and the activity coefficients. A significant advantage of the model lies in its ability to predict the thermodynamic properties of liquid alloys using only binary infinite dilution activity coefficients. The thermodynamic activities and activity coefficients of components of the related Si-Fe, Si- Al and Fe-Al binary and the Si-Fe-Al ternary alloy systems are calculated based on the MIVM. The computational activity values are presented graphically, and evaluated with the reported experiment data in the literature, which shows that the prediction effect of the proposed model is of stability and reliability.


Author(s):  
R. W. Vook ◽  
R. Cook ◽  
R. Ziemer

During recent experiments on Au films, a qualitative correlation between hole formation and deposition rate was observed. These early studies were concerned with films 80 to 1000A thick deposited on glass at -185°C and annealed at 170°C. In the present studies this earlier work was made quantitative. Deposition rates varying between 5 and 700 A/min were used. The effects of deposition rate on hole density for two films 300 and 700A thick were investigated.Au was evaporated from an outgassed W filament located 10 cm from a glass microscope slide substrate and a quartz crystal film thickness monitor. A shutter separating the filament from the substrate and monitor made it possible to obtain a constant evaporation rate before initiating deposition. The pressure was reduced to less than 1 x 10-6 torr prior to cooling the substrate with liquid nitrogen. The substrate was cooled in 15 minutes during which the pressure continued to drop to the mid 10-7 torr range, where deposition was begun.


Author(s):  
E. C. Buck ◽  
N. L. Dietz ◽  
J. K. Bates

Operations at former weapons processing facilities in the U. S. have resulted in a large volume of radionuclidecontaminated soils and residues. In an effort to improve remediation strategies and meet environmental regulations, radionuclide-bearing particles in contaminant soils from Fernald in Ohio and the Rocky Flats Plant (RFP) in Colorado have been characterized by electron microscopy. The object of these studies was to determine the form of the contaminant radionuclide, so that it properties could be established [1]. Physical separation and radiochemical analysis determined that uranium contamination at Fernald was not present exclusively in any one size/density fraction [2]. The uranium-contamination resulted from aqueous and solid product spills, air-borne dust particles, and from the operation of an incinerator on site. At RFP the contamination was from the incineration of Pu-bearing materials. Further analysis by x-ray absorption spectroscopy indicated that the majority of the uranium was in the 6+ oxidation state [3].


1963 ◽  
Vol 13 (8) ◽  
pp. 329-334
Author(s):  
A. G. Ward ◽  
G. H. Broomfield
Keyword(s):  

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