Chemical and toxicological properties of coal fly ash - University of ...

with ultrapure water. The final HClO4 concentration (5%) was within therange compatible with ICAP techniques. Diluted solutions were stored in60-mL polyethylene bottles and refrigerated unt i 1 analysi s.Results for the particle size determinations are presented in Table 2.Most of the samples fell within the silt category (USDA soilclassification), predominantly in the 8- to 31-micron range. The siltsizedcomponent of the ashes (less than 62-micron- to 2-micron-diameterparticles) ranged from 53 to about 90 percent (Table 2). The particle sizedistribution of three of the fly ashes is shown in Figure 3; these sampleswere selected for the illustration as best demonstrating the variabilityand range of the textural distributions of the samples. Fly ash I 2 was asilt loam; I6 and I7 were both loams. The specific gravity of the flyashes (Table 2) ranged from 2.2 to 3.1 c~/crn3; the Illinois Basin samplesaveraged about 2.4. Comparable measurements have been reported elsewhere(EPKI, 1979).Chetnical and mineralogical analyses of the fly ash sasples indicated thatthe ashes generated from I1 1 inoi s Basin coals (samples I 1 -19) consistedDiameter (pm) ISGS 1981Figure 3. The particle size distribution in fly ashes 12, 16, and 17.