Definition of fines

i. Finely crushed or powdered material, e.g., of coal, crushed rock, or ore, as contrasted with the coarser fragments; esp. material smaller than the minimum specified size or grade, such as coal with a maximum particle size less than 3.2 mm, or ores too pulverulent to be smelted in the ordinary way; or material passing through a given screen or sieve.

Ref: AGI

ii. An engineering term for the clay- and silt-sized soil particles (diameters less than 0.074 mm) passing U.S. standard sieve No. 200.

Ref: AGI

iii. See Also: anthracite fines