milling (grinding)

https://doi.org/10.1351/goldbook.M03928
The mechanical reduction of the particle size of a sample by attribution (friction), impact or cutting. The required particle size of a sample is related to the size of the @T06284@ and the number of particles required to ensure homogeneity among test portions. The reduction in particle size may sometimes result in particles of different hardness and density, which produces inhomogeneity during the preparation of the @T06285@ or during the withdrawal of the @T06284@.
Source:
PAC, 1990, 62, 1193. (Nomenclature for sampling in analytical chemistry (Recommendations 1990)) on page 1205 [Terms] [Paper]