Non-settling Slurry
A slurry in which the solids do not settle to the bottom, but remain in suspension for a long time. A non-settling slurry acts in a homogeneous, viscous manner, but the characteristics are non-Newtonian. Particle size: less than 60-100 µm. A non-settling slurry can be defined as a homogeneous mixture. (A mixture of solids and liquid in which the solids are uniformly distributed.)
Settling Slurry
This type of slurry settles fast during the time relevant to the process, but can be kept in suspension by turbulence. Particle size: greater than 100 µm. A settling slurry can be defined as a pseudo-homogeneous or heterogeneous mixture and can be completely or partly stratified. (A mixture in which all the particles are in suspension but where the concentration is greater towards the bottom).
Newtonian Liquids
Newtonian liquids give a shearing stress that is linear and proportional to the velocity gradient, or the shearing rate. Water and most liquids are Newtonian.
Non-Newtonian Liquids
Some liquids, such as water-based slurries with fine particles, do not obey the simple relationship between shearing stress and shearing rate. They are referred to as non-Newtonian liquids.
