Agglomerates

The term agglomerate comes from the Latin (agglomerare – to accumulate, to agglomerate) and in process engineering describes the accumulation or “agglomeration” of previously loose components – e.g. granules or powder – into a solid compound^.1 The terms “lumping” or “grain enlargement” are also used in this context. The resulting composite is produced by processes such as sintering or pressing and, in contrast to “conglomerates”, is characterized by relatively uniform grain or granule sizes. Agglomerates are therefore enlarged particles that are formed from smaller particles or solids using the agglomeration process.

What are agglomerates?

Agglomerates are particle assemblies that are formed by smaller particles sticking together. In this process, the smaller particles are bonded together to form larger and stable agglomerates. This process can take place in a variety of ways, including mechanical, thermal or chemical methods. Agglomerates are used in many industries, particularly in areas such as chemicals, food processing, pharmaceuticals, mining and environmental technology.

The importance of agglomerates in the industry

Agglomerates play a crucial role in numerous industrial processes. They can be used to improve the handling of powders, increase the flowability of materials, improve the solubility of substances, facilitate dosing and increase the stability of products. Agglomerates can also have specific properties such as porosity, particle size and hardness that make them particularly suitable for certain applications.

The agglomeration process

The agglomeration processes used to form agglomerates are diverse and vary depending on the materials to be processed and the desired properties of the agglomerates. Ebbecke Verfahrenstechnik specializes in offering tailor-made agglomeration solutions for customers. Some of the most common agglomeration processes are explained below:

1. Mechanical agglomeration
   Mechanical agglomeration involves the application of mechanical force to bind the particles together. This can be done by rolling, mixing, stirring or kneading the particles. The process can be assisted by the addition of binders to better hold the particles together. Mechanical agglomeration is often used in the food industry to produce products such as cereal bars, granules or instant beverage powders.

2. Thermal agglomeration
   In thermal agglomeration, the particles are joined together by heat treatment. By heating the particles, they melt or soften at the contact points and combine to form larger agglomerates, which remain stable after cooling. This process is often used to produce metal agglomerates or to solidify powdery materials.

3. Chemical agglomeration
   Chemical agglomeration is based on the use of chemicals to bind and agglomerate the particles. This can be done by adding binders, liquids or solutions that have a reactive effect on the particle surface. Chemical agglomeration is often used in the mining industry to agglomerate ore and improve the beneficiation process.

Areas of application for agglomerates

Typical examples of agglomerates in food technology are soluble coffee powder, instant powder for drinks and other convenience products. Agglomerates are also frequently used in the pharmaceutical industry, for example in tablets or as a thickener in liquid meals.

Agglomeration process

Agglomeration is one of the four main process groups in mechanical process engineering. In the field of agglomerates, a basic distinction is made between pressing and build-up agglomeration processes, fluidized bed granulation, mixed agglomeration and re-mixing agglomeration.

During sintering, the fine-grained materials to be joined are heated to allow the molecules to bond to the melting surfaces of the individual particles.

Tablets, pellets and briquettes are produced by compression agglomeration – also known as compression molding.

The flocculation process, on the other hand, allows solid particles in liquids to form larger particle clusters, making it easier to filter them out.

Advantages of agglomeration

The aim of agglomeration is to improve the properties of materials – for example, by optimizing pourability or reducing dust in powders and mixtures. Agglomeration can also improve the storage and handling of materials.

Agglomerates, such as those resulting from fluidized bed drying, are easy to dose and ideal for stirring into water or other liquids. Due to the low proportion of fine dust, the hygienic environmental conditions in the manufacturing process can also be improved and maintenance and cleaning costs minimized.

Processing at Ebbecke Verfahrenstechnik

At Ebbecke Verfahrenstechnik in Bruchköbel, agglomerates are processed in contract grinding. Using various techniques such as centrifugal screening and machines such as the Fine Mill, these compounds can be broken up and further processed. Contact us and let us advise you, we will be happy to help you!