Formation of secondary minerals in artificially weathered fly ash
A leaching experiment was designed to evaluate the chemical, mineralogical, and morphological nature of precipitation products formed during the accelerated laboratory weathering of an alkaline fly ash. The ash, classified as alkaline Modic, was leached with 0.005 mol L/sup -1/ H/sub 2/SO/sub 4/ in a series of five leaching columns for a period of approximately 90 d. The weathered residues were characterized by x-ray diffraction, differential thermal analysis, infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Three types of precipitation products were identified in the ash. Calcite formed through the dissolution of Ca from the ash and subsequent reaction with CO/sub 2/ absorbed by the initial alkaline leaching solutions. Iron, dissolved from the ash under acidic conditions, precipitated as amorphous coatings on fly ash particles. Aluminum and Si dissolved from the glass of the ash was translocated and precipitated within alkaline environments as an amorphous aluminosilicate material best described as proto-imogolite. Results indicated that the products of weathering of fly ash in terrestrial environments are similar to those documented for alkali soils and some soils of volcanic origin.
- Research Organization:
- Univ. of Alberta, Edmonton
- OSTI ID:
- 5300897
- Journal Information:
- J. Environ. Qual.; (United States), Journal Name: J. Environ. Qual.; (United States) Vol. 14:3; ISSN JEVQA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010600* -- Coal
Lignite
& Peat-- Properties & Composition
AEROSOL WASTES
ALKALINE EARTH METALS
ALUMINIUM
ASHES
CALCIUM
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL COMPOSITION
COAL
COHERENT SCATTERING
DATA
DIFFERENTIAL THERMAL ANALYSIS
DIFFRACTION
DISSOLUTION
ELECTRON MICROSCOPY
ELEMENTS
ENERGY SOURCES
EXPERIMENTAL DATA
FLY ASH
FOSSIL FUELS
FUELS
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ACIDS
IRON
LEACHING
MATERIALS
METALS
MICROSCOPY
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PARTICLES
PARTICULATES
RESIDUES
SCANNING ELECTRON MICROSCOPY
SCATTERING
SEPARATION PROCESSES
SOILS
SOLID WASTES
SULFURIC ACID
THERMAL ANALYSIS
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY
WASTES
WEATHERING
X-RAY DIFFRACTION