Degree of fineness

A mill that grinds or pulverizes fuel such as PF coal to a prescribed degree of fineness. Typically, 70% of PF will pass through a 200 mesh (74 micron) screen. 

A wide range of particle sizes is produced to suit different applications. Initially milling only has to break the relatively weak bonds between crystals of calcite, but for the finer products fracture of these crystals has to occur. Dry milling is used for the coarser fractions, but milling costs rise steeply as the degree of fineness increases until it becomes more economic to use wet milling, despite the additional drying costs. Eventually, as the required particle size is reduced even further, precipitation becomes the most economic procedure. 

The nitrocellulose used for the manufacture of the mass consisted of a mixture of two qualities high-nitrated nitrocellulose S (13.15-13.25% N), with a solubility of about 10% and a degree of fineness of about 85 cm and low-nitrated nitrocellulose EH (11.3-11.45% N), with a solubility of 100% and a degree of fineness of about 90 cm. 

During the various operations enumerated samples are taken to be checked in the laboratory for stability (Abel heat test), degree of fineness, etc. 

The rate of detonation of ammonium nitrate depends to a large extent on the degree of fineness, the initiator, the density, and the confinement of the charge. It varies within wide limits, from 1100 to 2700 m/sec. 

ISO 972 1997 Chillies and capsicums, whole or ground (powdered) - specification ISO 7540 1984 Ground (powdered) paprika (Capsicum annuum L.) - specification ISO 3588 1977 Determination of degree of fineness of grinding - hand-sieving method (reference method)... 

D. Place a few drops of the stirred mixture from Identification Test A on a microscope slide, and insert a coverglass. Observe at 100 magnifications with a microscope. Fibers and fiber fragments are visible, regardless of the degree of fineness of the sample. 

Does Fire then so attenuate and divide such a Body, that those corpuscules which are thus fluid, are in reality the very Elements of the Bodies, so long as they continue in this state. And is this the reason, that the particles of Metals, when in fusion, are so intimately mingled one among another, that it is impossible to reduce them to the same degree of fineness by any other method. ... 

---