Agglomeration porosity

Agglomerate porosity can be measured by gas adsorption or mercuiy porosimetiy. However, any breakage or compression of the granules under high pressure during porosimetiy can invahdate the results. 

Agglomerate porosity and density. This is closely related to product strength. Pressure methods are well suited to control of porosity which may be needed in some applications. 

Figure 57. Approximation of the theoretical tensile strength of agglomerates as a function of size of the particles forming the agglomerate. Porosity e = 0.35...

Typical Agglomerate Porosities Different agglomeration methods yield different porosities of the resulting agglomerates. In this respect, three methods with several subgroups can be distinguished ... 

Finally, because during high-pressure agglomeration porosity is often reduced to very low levels, post-treatment methods may be required to regain a more open pore structure and larger voids (see Section 5.3.2). 

Here, P is the adhesion force between two spheres, 8 the agglomerate porosity, and K the coordination number of the primary particles building the agglomerate. For spherical primary particles K is approximately equal to n/e. 

The stochastic approach treats the size enlargement process as an increase in the number of primary particles per agglomerate. In order to be able to compare the model results with a real process, this number is correlated with the agglomerate diameter by assuming a constant agglomerate porosity of 60%. The structure of the primary particles within the agglomerate is based on a concept of fractional... 

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