Conversion of coal wastes into waste-cleaning materials. Quarterly progress report, October 1--December 31, 1995

Technical Report · Sun Dec 31 04:00:00 EST 1995

DOI:https://doi.org/10.2172/251301· OSTI ID:251301

Shih, W H

The authors have been investigating the conversion of fly ash into mesoporous materials in the last several months. Although lamellar phase has been observed, the hexagonal phase has not. According to the literature, only the hexagonal phase survives after calcination. Therefore, the goal is to synthesize hexagonal mesoporous materials with fly ash. It was pointed out by Chen et al. that the Si/Al molar ratio in the precursor solution must be larger than 74 in order for the hexagonal mesoporous phase (MCM-41) to be formed. On the other hand, the Si/Al molar ratio in the fly ash is lower than 74. In the last three months, the authors did a systematic study on the effect of Si/Al molar ratio on the formation of MCM-41 phase. The Si/Al molar ratio was varied from 148 to 1, the smallest ratio allowed by the Loewenstein rule. It was found that the amount of Al in the precursor solution can be as high as Si/Al=1 without disrupting the formation of aluminosilicate mesoporous materials (MCM-41). As the Si/Al ratio in the precursor solution was varied, the structure and the physical properties of the MCM-41 materials were changed. Lower Si/Al ratios tend to have a smaller shrinkage in the d{sub 100}-spacing after calcination and have higher X-ray diffraction intensity. Results indicate that as the Al content increases, the MCM-41 materials tend to have a thicker cell wall.

• Research Organization: Drexel Univ., Philadelphia, PA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-94PC94215
• OSTI ID: 251301
• Report Number(s): DOE/PC/94215--T6; ON: DE96012092
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
36 MATERIALS SCIENCE
ADSORBENTS
ALUMINIUM
CALCINATION
CONCENTRATION RATIO
CRYSTAL STRUCTURE
FLY ASH
PHASE STUDIES
POROUS MATERIALS
PROGRESS REPORT
SILICON
SURFACE AREA
SYNTHESIS
WASTE PRODUCT UTILIZATION