Synthesis and characterization of iodosodalite
- Materials Science and Engineering Program, Washington State University, Pullman Washington
- School of Chemical Engineering and Bioengineering, Washington State University, Pullman Washington; Pacific Northwest National Laboratory, Richland Washington
- School of Mechanical and Materials Engineering, Washington State University, Pullman Washington
- Materials Science and Engineering Program, Washington State University, Pullman Washington; Pacific Northwest National Laboratory, Richland Washington
- Materials Science and Engineering Program, Washington State University, Pullman Washington; Pacific Northwest National Laboratory, Richland Washington; School of Mechanical and Materials Engineering, Washington State University, Pullman Washington
The effects of six process variables on the hydrothermal growth of iodosodalite, Na8Al6Si6O24I2, were investigated: pH (NaOH concentration), aging time, temperature, Al/Si ratio, the precursors used (i.e., zeolite 4A, kaolinite, meta-kaolin, colloidal silica, and sodium aluminate), and precursor concentration. Powder X-ray diffraction (XRD) was performed to identify phases and Rietveld refinements were used to quantify mass fractions of phases. Iodosodalite yield increased as aging time and pH increased. The crystallization of iodosodalite was favored in the temperature range 140-180 °C whereas, at 200 °C, basic cancrinite formed at the expense of some iodosodalite. Decreasing the Al/Si ratio by half increased the crystallization of basic cancrinite. Lowering the precursor concentration by adding water revealed the crystallization of nepheline hydrate I and a decrease in the sodalite fraction. Among the tested precursors, zeolite 4A yielded the highest mass fraction of iodosodalite in the synthesized powders. From the aging time and temperature variation experiments, the phase transformation of zeolite A → sodalite → cancrinite was observed. The crystallization of various minerals suggests that mechanisms for transport of the ions and formation of the aluminosilicate frameworks vary with hydrothermal conditions.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1363988
- Report Number(s):
- PNNL-SA--119593; 830403000
- Journal Information:
- Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 5 Vol. 100; ISSN 0002-7820
- Publisher:
- American Ceramic Society
- Country of Publication:
- United States
- Language:
- English
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