MECHANICAL TREATMENT OF FLY ASHES .1. PHYSICOCHEMICAL CHARACTERIZATION OF GROUND FLY ASHES

Physico-chemical characteristics of mechanically treated By ashes are investigated. An original fly ash was ground, using a laboratory mill, for several times (from 10 to 60 minutes). Respect to physical charac terization, fineness increasing of samples with grinding time was obse rved, but loss of effectiveness occurred for grinding time longer than 20 minutes. Ground samples showed higher specific gravity probably du e to the presence of cenospheres in the original By ash. Only a little change in mineralogical composition of fly ashes was observed when gr inding: calcium carbonate formation by reaction of calcium oxide with carbon dioxide. Chemical behavior (pH and conductivity) of fly ash/wat er suspensions were studied and acid neutralization capacities measure d.