Are fly ash classification and grading properties the same?

According to the content of free calcium oxide in fly ash, it is usually divided into F type (low calcium ash), C type (high calcium ash) and composite ash. According to the fineness of fly ash, it is usually divided into grade I, grade II and grade III.

First-class fly ash fineness: refers to the sieve allowance of 45μm square hole sieve not more than 12%, that is, the 45μm pass rate often said in the micropowder industry is 88% (45μm is equivalent to 325 mesh)

Secondary fly ash fineness: the allowance of 45μm square hole sieve is not more than 20%

Three-level fly ash fineness: the allowance of 45μm square hole sieve is not more than 45%