granulometria

Granulometría, or granulometry, is the study and measurement of the size distribution of particles in a granular material. It characterizes the proportion of particles that fall within specific size ranges and is used in geoscience, soil science, civil engineering, materials science, mining, and pharmaceuticals. The result is a granulometric distribution, often presented as a curve of cumulative passing percentage against particle size or as tables of the percentage passing through a series of sieves.

Common methods include sieve analysis, suitable for coarse to medium grains, typically performed dry or with washing; hydrometer or sedimentation analysis for finer particles using Stokes’ law; and laser diffraction or dynamic light scattering to cover a wide size range. Image analysis may supplement traditional techniques. International standards govern these procedures, such as ASTM D422 and ISO 13320 for instrument-based methods.

Key descriptors derived from granulometric data include D10, D50 (the median), D90, and the distribution span. The granulometric curve supports classification as well-graded or poorly graded and as fine or coarse. In geology and soil science, the material is described by proportions of gravel, sand, silt, and clay, which underpin soil classification systems such as the Unified Soil Classification System (USCS).

Applications span soil characterization for construction and geotechnical design, quality control of aggregates for concrete and asphalt, ceramic and ceramic powder processing, pharmaceutical granulation, and mining or environmental projects where particle size affects transport, reaction rates, or filtration.