2016-1-12 · 2016-1-12 · Optimization of a Tertiary Crushing Stage Background Some limestone quarries in the Mid West produce excessive amounts of fines <4# (<4.7mm) A typical "modern" crusher produces 19-21% A typical "old" crusher produces 14-15% Modern crushers have high power input/draw which is achieved by large throws, BUT these machines produce more fines.