Spray Drying - Examples and Results

Both the spherical shape of the granules and the way spheres pack together in a powder holder ensures random arrangement of the component particles. In addition, indeed as a consequence of eliminating preferred orientation, the XRPD patterns of spray dried samples are extremely reproducible as illustrated below.

Examples of spray dried materials

Spray dried kaolinite.	Spray dried smectite.
Spray dried muscovite.	Spray dried talc, illustrating the effect of particles which are slightly too large.
Spray dried shale.	Spray dried quartz showing internal structure. Fines migrate to the outside during drying.
Backscattered electron image of section through granules (spray dried sandstone).	Backscattered electron image of section through granules (spray dried sandstone).

Examples of spray dried and non spray dried powder x ray diffraction patterns.

XRPD patterns of a synthetic mixture of 25% chlorite, 25% muscovite, 25% albite and 25% calcite, all minerals which frequently exhibit preferred orientation. A) XRPD patterns from 18 separate loadings of a freeze-dried portion of the mixture by 3 different operators (red, green, blue, 6 patterns each). B) XRPD patterns from 18 different loadings of a spray-dried portion of the mixture by 3 different operators (red, green, blue, 6 patterns each).

For further information please contact Steve Hillier.