Homogenisation of solids

Multiple phases. Natural or artificial (manufactured) solids can be composed in several phases. The quality of the dispersion of these phases one in the other will allow the analyst to benefit from similar test samples within the entire batch of material. Material sciences teach us that the degree of homogeneity of the mixture will depend on the nature of the mixed phases and, in particular, the size of the solid particles, the particle size distribution and the respective density. The more similar the density and the particle size, the better is the achieved homogeneity. To achieve similar test samples, even for very small particle sizes, requires a narrow particle size distribution. Muntau et al. [29-30], Griepink et al. [31] and Pauwels et al. [32] have studied the relation between particle size and minimum sample intake. They have demonstrated that a major factor for homogeneity of small sample intakes is the low particle size of the solid material and their size distribution. This aspect will be discussed in more details in the section on homogeneity testing. 

Solid materials are composed of various dispersed phases, e.g. alumino-silicates, oxides, organic matter in soils, fat and fibres in tissues of animal organs etc. Within 

When properly ground and mixed, the material can be brought to a stage where very small portions are representative of the whole batch of material. When no difference between these small portions can be detected the material is called homogeneous for the studied test portion or sample intake. The smaller this portion is, the better the homogeneity. 

EXAMPLES OF GRINDING MACHINES FOR THE PREPARATION OF SOLID MATRIX CRMS. SIMILAR TABLES COULD BE PREPARED FOR MIXING, SIEVING AND PARTICLE SIZE DETERMINATION DEVICES. MORE INFORMATION CAN BE FOUND FROM SUPPLIERS AND IN REF. [5A 57] 

Type of maehme Function Capacity Type of material or matrix Remark 

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