Material data sheet fly ash (astm c 618 class f )" properties unit smart stones spec loss of ignition % 1.5 max sio2 silicon dioxide % 50-60 sio2 + al2o3 + fe2o3 % 75-85 so3 sulfur tri-oxide % 1 max cl chloride % 0.01 na2o sodium oxide alkali % 1.5 max mgo magnesium oxide % 2.5-3.00 autoclave expansion % 0.8 more...