Suspension

Suspension is understood to mean a heterogeneous mixture of substances, consisting of a liquid, and solid bodies dispersed therein. Suspending is understood as the process of combining these two substances. Depending on the size of the dispersed solids, homogeneous or heterogeneous mixtures are formed, which are then also referred to as dispersion. Dispersions with the smallest particles, the colloids, are then referred to as colloidal dispersion and are located between the true solutions and the coarsely dispersed suspensions. These colloidal dispersions include the gels. The solid bodies are, for example, slurried and held in suspension by the use of an agitator and usually with the aid of a dispersant. A suspension, which is also referred to as coarse particle dispersion, has a strong tendency to sedimentation.  
Due to the size of the particles, suspensions are divided into two groups, into “coarse suspensions” (e.g. chalk slurry) and “fine suspensions” (e.g. lime water/milk). In the case of still finer dispersed particle, one speaks of a dispersion.

Our innovative Dosing Station ensures efficient weighing and dosing of liquid raw materials in the process chain.

Our range of services also includes consulting and the sale of used homogenising mixers, which are used for the suspension process.

Applications

Many liquids used in everyday life are suspensions. Orange juice, cocoa and wheat beer are just a few examples from the food sector. Mortar and concrete are mineral suspensions. In the photovoltaic and semiconductor industries, suspensions of silicon carbide and polyethylene glycol are used to cut wafers.  
A few example applications can be found here:

• Suspensions
• Food supplements

Details

When suspending, it is most important that a mixture is produced which is as homogeneous as possible, although it will never be a homogeneous mixture of substances. The solid phase remains as particles and will never dissolve completely. In order to obtain this homogeneous mixture, agglomerates must be broken down and stabilising additives must be added and finely distributed.  
Appropriate homogenisers, which provide high flow velocities in all parts of the vessel whilst providing a sufficient level of energy input, should be used to achieve efficient production and excellent product quality. If a suspension is to be permanently held in suspension and thereby stabilised, this is often dispersed in an emulsion.

We will be pleased to advise you on the subject of suspension.