Particle segregation
Encyclopedia
In Particle Segregation particulate solid
s tend to segregate by virtue of differences in the size, density
, shape and other properties of particles of which they are composed. The process of segregation occurs during as well as during subsequent handling of completed mix and it is pronounced with free flowing powders. Powders that are not free flowing or that exhibit high forces of cohesion or adhesion between particles of similar or dissimilar composition are often difficult to mix owing to agglomeration
. The clumps of particles can be broken down in such cases by the use of mixtures that generate high shear forces or that subject the powder to impact. When these powders have been mixed, however, they are less susceptible to segregation because of the relatively high interparticulates forces that resist interparticulate motion leading to unmixing.
Solid
Solid is one of the three classical states of matter . It is characterized by structural rigidity and resistance to changes of shape or volume. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a...
s tend to segregate by virtue of differences in the size, density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
, shape and other properties of particles of which they are composed. The process of segregation occurs during as well as during subsequent handling of completed mix and it is pronounced with free flowing powders. Powders that are not free flowing or that exhibit high forces of cohesion or adhesion between particles of similar or dissimilar composition are often difficult to mix owing to agglomeration
Agglomeration
In the study of human settlements, an urban agglomeration is an extended city or town area comprising the built-up area of a central place and any suburbs linked by continuous urban area. In France, INSEE the French Statistical Institute, translate it as "Unité urbaine" which means continuous...
. The clumps of particles can be broken down in such cases by the use of mixtures that generate high shear forces or that subject the powder to impact. When these powders have been mixed, however, they are less susceptible to segregation because of the relatively high interparticulates forces that resist interparticulate motion leading to unmixing.
Segregation mechanisms
The five major segregation mechanisms are- Sifting
- Angle of repose
- Fines fluidization
- Air entrainment
- Chute trajectory