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Precipitation and Crystallization Processes in Reprocessing, Plutonium Separation, Purification, and Finishing, Chemical Recovery, and Waste Treatment
Published in Reid A. Peterson, Engineering Separations Unit Operations for Nuclear Processing, 2019
Calvin H. Delegard, Reid A. Peterson
While only the PUREX Process was used at SRS, Hanford also used the Bismuth Phosphate and REDOX Processes and thus has much more variable and complicated waste compositions. As a result, other salts also are crystallized in the Hanford tank wastes including sodium oxalate (Na2C2O4); sodium aluminate (NaAl(OH)4); and double salts such as sodium nitrate sulfate, darapskite or (Na3NO3SO4 ∙ H2O); sodium fluoride sulfate, kogarkoite or (Na3FSO4); sodium aluminum carbonate hydroxide, dawsonite or (NaAlCO3(OH)2) (Herting et al. 2015; Reynolds et al. 2013); and many other crystalline and non-crystalline (amorphous) solid phases (see Tables 2-1 and 5-1 of Harrington 2011; Peterson et al. 2018).
Spectroscopic Methods
Published in Michael Dornbusch, Corrosion Analysis, 2018
In Fig. 3.47 the aluminium surface is covered with a layer containing hydroxide structures visible with the corresponding bands at 3486cm-1 $ 3486\,{\text{cm}}^{ - 1} $ ,1011cm-1 $ 1011\,{\text{cm}}^{ - 1} $ , 768cm-1 $ 768\,{\text{cm}}^{ - 1} $ and 687cm-1 $ 687\,{\text{cm}}^{ - 1} $ . A carbonate structure like Dawsonite should be visible by the bands at 1649cm-1 $ 1649\,{\text{cm}}^{ - 1} $ , 1485cm-1 $ 1485\,{\text{cm}}^{ - 1} $ and 843cm-1 $ 843\,{\text{cm}}^{ - 1} $ (compare Table 5.6 in the app.). This spectrum shows the limitation of the method. If the layer is very thin and has no intensive signals, the noise caused by atmosphere dominates the spectrum.
Preparation of pseudo-boehmite through the dawsonite as an intermediate
Published in Inorganic and Nano-Metal Chemistry, 2020
Zhihua Zhao, Renjie Wang, Xiaoqi Peng, Penghui Deng, Ye Tian, Ziran Liu, Pu Shi, Lihui Wu, Zhongwei Zhang, Chen Chen, Chunbo Liu
It has now been surprisingly discovered that the structure of PB can be produced in a tunable and economical process which avoids all the difficulties presented by the prior art methods. The present work involves a process for the conversion of dawsonite to PB under a moderate condition. More specifically, the work involves a more complete and industrial operation for the conversion of dawsonite to PB than the previous state of the art process disclosed in US. Pat. No. 3,739,062.[39] In the present work, NaAlO2 and NH4HCO3 were used as starting materials to synthesize dawsonite. We choose dawsonite as the intermediate compound to transform NaAlO2 into PB. In this way, dawsonite was firstly obtained via the direct precipitation of NH4HCO3 and NaAlO2 solution in certain conditions, after that, by adding glacial acetic acid to dawsonite aqueous slurry and varying pH value from 11 to 5, we are able to synthesize PB with different pore structures and large pore volume. As dawsonite can transform into PB with different crystal structures simply through moderating system acidity, the formation and phase transformation process from dawsonite to PB was also discussed.