Surface adhesion of low-rank coal ash: Quarterly report, April 1986-June 1986

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

OSTI ID:7230570

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

The adhesive properties of ion-exchanged Center lignite ash were evaluated using the sticking apparatus. ASTM ash from ion-exchanged Center lignite was suspended on a platinum and heated in a methane-oxygen flame of adiabatic temperature between 1650/sup 0/ and 1750/sup 0/C. The resultant molten slag was dropped onto an oxidized carbon steel surface. The ion-exchanged Center lignite ash had a sticking temperature of 550/sup 0/C. The sticking temperature of the raw Center lignite ash was considerably lower (approx.375/sup 0/C) as reported previously. The higher sticking temperature of the ion-exchanged ash was probably due to removal of sodium and calcium from the Center lignite. The gas-fired vertical tube furnace was used to form deposits with Center lignite, San Miguel lignite, Rosebud sub-bituminous coal and Navajo sub-bituminous coal. The objectives of these tests were to evaluate (1) the effect of oxygen partial pressure during combustion on deposit characteristics of the four coals and (2) the effect of hot zone temperature on deposit characteristics of Rosebud and Navajo sub-bituminous coals. Increasing the furnace oxygen partial pressure from 20 to 60% O/sub 2/ was generally found to decrease the deposit formation rates and strengths. X-ray diffraction analyses of deposits formed during the 60% O/sub 2/ tests indicated that less alkali/silica interactions had occurred compared to the tests performed with 20% excess air. Decreasing the furnace hot zone temperature was found to decrease deposit formation rate and strength for the Rosebud coal. These trends were also observed for Rosebud coal which had been ion-exchanged. 3 refs., 5 figs., 6 tabs.

• Research Organization: Pennsylvania State Univ., University Park (USA). Coll. of Earth and Mineral Sciences
• DOE Contract Number: AC21-85FC10627
• OSTI ID: 7230570
• Report Number(s): DOE/FC/10627-2229; ON: DE87003707
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
ADHESION
ASHES
BOILERS
BROWN COAL
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COAL
COHERENT SCATTERING
COMBUSTION
DEPOSITS
DIFFRACTION
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
LIGNITE
MATERIALS
NONMETALS
OXIDATION
OXYGEN
PARTIAL PRESSURE
RESIDUES
SCATTERING
SLAGS
SUBBITUMINOUS COAL
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
X-RAY DIFFRACTION