A suspension is a heterogeneous mixture of a finely distributed solid in a liquid. The solid is not dissolved in the liquid, as is the case with a mixture of salt and water.

Examples of Suspensions

  • Slurry of sand in seawater
  • Orange juice
  • Wheat beer
  • Blood
  • Concrete or mortar
  • Drilling mud

What Characterizes a Suspension?

Suspensions separate over time due to gravity. The solid settles on the ground or forms a sediment, for example, in tanks or containers.

Stable suspensions can form with very small solid particles (particle size below 1 µm). The fine particles are held in suspension by molecular movement. The particles separate very slowly from the liquid or not at all. These solids are called colloids.

To accelerate the process of sedimentation in a suspension (for example, in chemistry), centrifuges can be used. Centrifugal force separates the solid particles from the liquid.



[1] Duden: Suspension,, 05/2019

[2] Bundesverband Geothermie 05/2019: Suspension,, 05/2019

[3] Spektrum Akademischer Verlag: Suspension, in: Lexikon der Biologie,

, 1999