We Energies Coal Combustion Products ... - The White House

Table 2-9 shows the chemical composition of boiler slag. The chemical
composition of boiler slag is similar to that of bottom ash, as shown in Table
2-4, though the production process of boiler slag and bottom ash is relatively
different.
Table 2-10 gives the typical geotechnical properties of the boiler slag. The
friction angle of boiler slag is within the same range as those for sand and
other conventional fine aggregates. Boiler slag exhibits high CBR value,
comparable to those of high-quality base materials. Compared to bottom ash,
boiler slag exhibits less abrasion loss and soundness loss resulting from its
glassy surface texture and lower porosity (9).
Table 2-9: Chemical Composition of Selected Boiler Slag (9)
Compound Symbol Boiler Slag from
Bituminous Coal %
(Mass)
Boiler Slag from Lignite
Coal % (Mass)
Silicon Dioxide SiO 2 48.9 40.5
Aluminum Oxide Al 2 O 3 21.9 13.8
Iron Oxide Fe 2 O 3 14.3 14.2
Calcium Oxide CaO 1.4 22.4
Magnesium Oxide MgO 5.2 5.6
Sodium Oxide Na 2 O 0.7 1.7
Potassium Oxide K 2 O 0.1 1.1
Table 2-10: Geotechnical Properties of Boiler Slag (9)
Property
Boiler Slag
Specific Gravity 2.3-2.9
Dry Unit Weight (lb/cu.ft) 60-90
Plasticity
None
Maximum Dry Density (lb/cu.ft) 82-102
Optimum Moisture Content (%) 8-20
Los Angeles Abrasion (%) 24-48
Friction Angle (°)
38-42
36-46 (