Definition - What does Wet Sieving mean?
Wet sieving, as its name suggests, is a particle size gradation technique involving the use of a liquid substance. This method involves applying a liquid (usually water) to the test sample and allowing fine particles to pass through the sieve while also breaking down agglomerates. The sample is then dried and assessed. Wet sieving is also used to prepare the granular sample for further particle size analysis (e.g., vibration sieving). Like other sieving methods, wet sieving is used to separate or measure particles by their size.
Corrosionpedia explains Wet Sieving
Wet sieving is ideal for samples with high concentrations of fine particles or for samples where particles are not easily broken down by mechanical shaking. For example, adhesive soils such as clay or silt can clump together, forming larger particles that do not fit through the mesh openings.
In this case, while the particles may seem to be solid and the correct size, they are in fact made up of several smaller particles. By "washing" the sample during wet sieving, these clumps are broken down, allowing for a more accurate gradation analysis.