Surface adhesion of low-rank coal ash: Quarterly report, January 1986-March 1986

Technical Report · Fri Aug 01 04:00:00 EDT 1986

OSTI ID:7174098

Austin, L G; Benson, S; Conn, R

The percent of ion-exchangeable cations was determined for the San Miguel lignite. The ion-exchanged material was produced by treating the lignite with ammonium acetate solution. The amounts of exchangeable sodium and calcium were found to be 98% and 76%, respectively. The adhesive properties of lignite ash and sub-bituminous ashes were evaluated using the sticking apparatus. ASTM ashes of these coals were suspended on platinum wire and heated in a methane-oxygen flame of adiabatic temperature between 1650/sup 0/ and 1750/sup 0/C. The resultant molten slags were then dropped onto oxidized mild steel and stainless steel surfaces with typical compositions and temperatures corresponding to boiler tubes. The San Miguel and Navajo ashes each formed highly viscous, porous slags which did not wet the steel substrates. Slag viscosity of the low-rank coal ashes may be more important for judging ash sticking tendencies than ASTM ash fusion temperatures. The ash viscosity predicted by empirical composition/viscosity correlations for the tested slags varied by one to two orders of magnitude from ash to ash whereas the ash fusion temperatures were fairly similar. A vertical tube furnace was used to grow deposits using combusted raw and ion-exchanged San Miguel lignite on cooled boiler steel substrates at conditions similar to those in a utility boiler. Strengths of the deposits were measured and correlated with deposit height and temperature. X-ray diffraction analysis was used to determine the crystalline phases present in bulk deposits.

• Research Organization: Pennsylvania State Univ., University Park (USA). Coll. of Earth and Mineral Sciences
• DOE Contract Number: AC21-85FC10627
• OSTI ID: 7174098
• Report Number(s): DOE/FC/10627-2228; ON: DE87003705
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600 -- Coal
Lignite
& Peat-- Properties & Composition
20 FOSSIL-FUELED POWER PLANTS
200101* -- Fossil-Fueled Power Plants-- Cooling & Heat Transfer Equipment & Systems
ADHESION
ASHES
BOILERS
BROWN COAL
CARBONACEOUS MATERIALS
CATIONS
CHARGED PARTICLES
CHEMICAL COMPOSITION
COAL
COHERENT SCATTERING
COMPARATIVE EVALUATIONS
DATA
DEPOSITS
DIFFRACTION
ENERGY SOURCES
EXPERIMENTAL DATA
FOSSIL FUELS
FOSSIL-FUEL POWER PLANTS
FUELS
INFORMATION
ION EXCHANGE
IONS
LIGNITE
MATERIALS
MECHANICAL PROPERTIES
MELTING POINTS
NUMERICAL DATA
PHYSICAL PROPERTIES
POWER PLANTS
RESIDUES
SCATTERING
SLAGS
SUBBITUMINOUS COAL
TEMPERATURE DEPENDENCE
TEMPERATURE EFFECTS
THERMAL POWER PLANTS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
VISCOSITY
X-RAY DIFFRACTION