What does elutriation mean?
Elutriation is the process of separating particles of different sizes or densities by washing them in a moving fluid, typically water or air. When a mixture is stirred into suspension, the lighter, finer particles remain suspended and are carried off with the fluid, while heavier, coarser grains settle to the bottom — allowing the fractions to be collected separately. The technique appears across many fields: chemists use it to grade powdered substances, soil scientists to sort sediment grains, and engineers in air-classification systems that separate dust from usable material. Derived from the Latin elutriare, 'to wash out,' the term carries an unmistakably scientific register and is rarely heard outside laboratory or industrial settings. Though largely displaced by mechanical sieving in some applications, elutriation remains valued where gentle, precise separation of very fine particles is required, making it a quietly enduring tool of practical science.
nounThe process of separating finer particles from coarser ones by washing or suspending them in water (or another fluid) and allowing the lighter material to be carried off while the heavier settles.
- The separation of fine particles from coarse ones by suspending them in a fluid so the lighter fraction is carried off and the heavier settles.
"The lab separated the clay from the sand by elutriation, decanting the fine suspension into a second vessel."
"The geologist used elutriation to isolate silt-sized grains from the riverbed sample."
"In wastewater treatment, elutriation helps wash fine solids out of sludge before further processing."
Usually uncountable when referring to the process generally; the plural appears when referring to individual instances or repeated operations.
"Repeated elutriations yielded increasingly pure fractions of the powder."
Before modern sieves, scientists sorted particles simply by pouring water over them and letting gravity do the work — a technique called elutriation that's still used in labs today.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of elutriation
Elutriation derives from the Latin verb elutriare, meaning 'to wash out,' formed from the intensive prefix e- plus lutriare, related to lavare ('to wash'). It entered English in the mid-seventeenth century as scientific writers adopted Latin technical vocabulary for laboratory processes. It shares its washing root with words such as dilute, ablution, and lotion, all tracing back to the same Latin family.
Related word forms
How elutriation is actually used
A formal, technical term found mainly in chemistry, soil science, pharmacology, and engineering contexts; rare in everyday speech.
Easily confused with elutriation
Elucidation means the act of making something clear or explaining it, whereas elutriation is a technical process of separating particles by washing.