TM 5-810-15
Table 3-4. Typical coal and ash analysis information suitable for boiler design. (Continued)
As Received (Raw)
Washed
Typical
Range
Typical
Range
Chlorine (%)
________
________to________
________
________to________
Sulfur (%)
________
________to________
________
________to________
Ash (%)
________
________to________
________
________to________
Oxygen (%)
________
________to________
________
________to________
Moisture (%)
________
________to________
________
________to________
Mineral Analysis
Phos. Penioxide, P205
________
________to________
________
________to________
Silica, SiO2
________
________to________
________
________to________
Ferric Oxide, Fe2O3
________
________to________
________
________to________
Alumina, Al2O3
________
________to________
________
________to________
Titania, TiO2
________
________to________
________
________to________
Calcium Oxide, CaO
________
________to________
________
________to________
Magnesium Oxide, MgO
________
________to________
________
________to________
Sulfur Trioxide, SO3
________
________to________
________
________to________
Potassium Oxide, K2O
________
________to________
________
________to________
Sodium Oxide, Na2O
________
________to________
________
________to________
Undetermined
________
________to________
________
________to________
Total
100.0
100.0
Reducing
Oxidizing
Fusion Temperature of Ash, deg. F
Initial Deformation (IT)
____________
____________
Softening (H=W)
____________
____________
Hemispherical (H= 1/2W)
____________
____________
Fluid (FT)
____________
____________
Free Swelling Index
________
________
Viscosity T250, deg. F
________
________to________
________
________to________
Silica Value
________
________to________
________
________to________
Base/Acid Ratio
________
________to________
________
________to________
Sulfur Forms
Pyritic Sulfur (%)
________
________to________
________
________to________
Sulfate Sulfur (%)
________
________to________
________
________to________
Organic Sulfur (%)
________
________to________
________
________to________
Water Soluble Alkalis
Water Soluble Na2O
________
________to________
________
________to________
Water Soluble K20
________
________to________
________
________to________
Equilibrium Moisture
________
________to________
________
________to________
Hardgrove Grindability Index
________
________to________
________
________to________
potential. One testing method of determining ash
3-5. Coal ash characteristics.
fusion temperature is prescribed in ASTM D 1857.
a. Slagging and fouling potential. The slagging
The test consists of observing the gradual thermal
potential of ash is the tendency to form fused de-
deformation (melting) of a pyramid shaped ash
posits on tube surfaces exposed to high
sample and recording the Initial Deformation
temperature radiant heat. The fouling potential is
Temperature (IT), Softening Temperature (ST),
the tendency of ash to bond to lower temperature
Hemispherical Temperature (HT), and Fluid
convection surfaces. The slagging and the fouling
Temperature (FT). The stages at which these
potential of the coal also directly affects furnace
temperatures are recorded are shown in figure 3-4.
design. Ash analyses of the expected fuel source
(2) Chemical analyses. The fusion
must be performed before undertaking the boiler
temperature of ash is influenced by the interaction
design, using ash prepared according to ASTM D
of the acidic oxide constituents silica dioxide
3174.
(SiO2), aluminum oxide (Al2O3), and titanium
(1) Fusion temperature. Many comparisons
dioxide (TiO2) with the basic oxides; ferric oxide
of chemical makeup have been developed to
(Fe2O3), calcium oxide (CaO), magnesium oxide
analyze the behavior of ash in boilers, empirical
(MgO), and potassium oxide (K2O)--all of which
testing of ash fusion temperature is still the most
are present in the coal ash in widely varying
basic way of predicting slagging and fouling
3-7
Previous Page
