Ion exchange kinetics of Cs⁺, SrOH⁺, and Rb⁺ for the hydrous crystalline silico-titanates, UOP IONSIV[trademark] IE910 and UOP IONSIV[trademark] IE911 /
UOP IONSIV[trademark] IE911 and UOP IONSIV[trademark] IE910 are novel hydrous crystalline silico-titanate ion enchanters. IONSIV[trademark] IE911 is a 400 gm diameter granular material made by binding together the 0.2 gm diameter IONSIV[trademark] IE910 crystals. IONSIV[trademark] IE911 is considere...
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[College Station, Texas] :
[Texas A & M University]
1999.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=733677981&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | UOP IONSIV[trademark] IE911 and UOP IONSIV[trademark] IE910 are novel hydrous crystalline silico-titanate ion enchanters. IONSIV[trademark] IE911 is a 400 gm diameter granular material made by binding together the 0.2 gm diameter IONSIV[trademark] IE910 crystals. IONSIV[trademark] IE911 is considered an excellent ion exchange material for treating United States Department of Energy radioactive waste. However, before such a treatment technology can be developed, it is vital that the kinetics of ion exchange on these new materials be understood both qualitatively and quantitatively. This research investigated the ion exchange kinetics of Cs⁺, SrOH⁺ and Rb⁺ on IE910 and IE911. A single solid phase resistance to diffusion was found to control the rate of ion exchange on IE910. Two resistances were found to contribute to the rate of ion exchange on IE911, a resistance to diffusion in the liquid filled pores between the crystals plus the solid phase resistance to diffusion inside the crystals. Mathematical models based on these mechanisms were written to simulate batch ion exchange experiments and the necessary diffusion coefficients were quantified by fitting these models to experimental data. In addition, a quantitative criterion was developed to determine the relative importance of the two resistances for IE911. This criterion indicates that the pore resistance is dominant for Cs⁺ exchange and controlling for Rb⁺ exchange. The criterion also predicts that the pore resistance is dominant for SrOH⁺ exchange. Thus, the solid phase resistance can be neglected without introducing a large error. This simplification significantly eases the future modeling efforts required to design the waste treatment process. Lastly, two concentration dependant forms of the IE910 solid phase diffusion coefficient were evaluated. Solid phase non-ideality considerations lead to the first form and solid phase electro-neutrality constraints lead to the second. Both forms yielded improved fits to experimental data over a constant solid phase diffusivity. |
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| Item Description: | Vita. "Major Subject: Chemical Engineering". In title, numerals and symbols are used. |
| Physical Description: | xv, 239 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 178-184). |