Size Reduction Flashcards
involves the production of smaller mass units from larger mass units of the same material
size reduction
for the larger solids, this is required to cause a fracture to take place
pressure
Because of the compressive loads applied to the crystal with irregular orientation this happens
fracture
hardness of material is measured by
Mohs Scale (1-10)
Criterion of materials’ resistance to crushing and has effect on wear and tear of size reduction device
Mohs scale
increasing scale of hardness based on Mohs scale
soft materials
intermediate hardness
hard materials
talc, gypsum and calcite is example of
soft materials
fluorite, apatite and feldspar are example of
intermediate hardness
quartz, topaz, corundum and diamond are example of
hard materials
properties of particles on size reduction
- particle size and shape
- specific surface and number of particles in a mixture
- specific surface in a mixture
- number of particles in a mixture
- average particle size
- particle size distribution in comminuted products
on specific surface of mixture, two screen analysis
- differential screen analysis
- cumulative screen analysis
three average particle size
- volume-surface mean diameter
- arithmetic mean diameter
- mass-means diameter
for particles too fine to sieve is dictated by
particle size distribution in comminuted products
in power requirement under size reduction, this states that the work required in crushing is proportional to the new surface created
rittinger’s law
in power requirement under size reduction, this states that the work required to form particles of size Dp from very large feed is proportional to the square root of the surface to volume ratio of the product
bond’s crushing law
