From Wikipedia, the free encyclopedia
Jump to: navigation, search
For the settlement in the North West province of South Africa, see Slurry, North West.
A slurry composed of glass beads in silicone oil flowing down an inclined plane

A slurry is a thin sloppy mud or cement or, in extended use, any fluid mixture of a pulverized solid with a liquid (usually water), often used as a convenient way of handling solids in bulk.[1] Slurries behave in some ways like thick fluids, flowing under gravity but are also capable of being pumped if not too thick.


Examples of slurries include:

  • Cement slurry, a mixture of cement, water, and assorted dry and liquid additives used in the petroleum and other industries[2][3]
  • Soil/cement slurry, also called Controlled Low-Strength Material (CLSM), flowable fill, controlled density fill, flowable mortar, plastic soil-cement, K-Krete, and other names[4]
  • A mixture of thickening agent, oxidizers, and water used to form a gel explosive[citation needed]
  • A mixture of pyroclastic material, rocky debris, and water produced in a volcanic eruption and known as a lahar
  • A mixture of bentonite and water used to make slurry walls
  • Coal slurry, a mixture of coal waste and water, or crushed coal and water[5]
  • Slurry oil, the highest boiling fraction distilled from the effluent of an FCC unit in a oil refinery. It contains large amount of catalyst, in form of sediments hence the denomination of slurry.
  • A mixture of wood pulp and water used to make paper
  • Manure slurry, a mixture of animal waste, organic matter, and sometimes water often known simply as "slurry" in agricultural use, used as fertilizer after ageing in a slurry pit
  • Meat slurry, a mixture of finely ground meat and water, centrifugally dewatered and used as food
  • An abrasive substance used in chemical-mechanical polishing
  • Slurry ice, a mixture of ice crystals, freezing point depressant, and water
  • A mixture of raw materials and water involved in the rawmill manufacture of Portland cement
  • A mixture of minerals, water, and additives used in the manufacture of ceramics
  • A bolus of chewed food mixed with saliva[6]
  • A composite slurry, formed from a combination of no less than three of the aforementioned slurries, as noted by Josh Latham.


Determining solids fraction[edit]

To determine the percent solids (or solids fraction) of a slurry from the density of the slurry, solids and liquid[7]

\phi_{sl}=\frac{\rho_{s}(\rho_{sl} - \rho_{l})}{\rho_{sl}(\rho_{s} - \rho_{l})}


\phi_{sl} is the solids fraction of the slurry (state by mass)
\rho_{s} is the solids density
\rho_{sl} is the slurry density
\rho_{l} is the liquid density

In aqueous slurries, as is common in mineral processing, the specific gravity of the species is typically used, and since SG_{water} is taken to be 1, this relation is typically written:

\phi_{sl}=\frac{\rho_{s}(\rho_{sl} - 1)}{\rho_{sl}(\rho_{s} - 1)}

even though specific gravity with units tonnes/m^3 (t/m^3) is used instead of the SI density unit, kg/m^3.

Liquid mass from mass fraction of solids[edit]

To determine the mass of liquid in a sample given the mass of solids and the mass fraction: By definition








and therefore



\phi_{sl} is the solids fraction of the slurry
M_{s} is the mass or mass flow of solids in the sample or stream
M_{sl} is the mass or mass flow of slurry in the sample or stream
M_{l} is the mass or mass flow of liquid in the sample or stream

Volumetric fraction from mass fraction[edit]




and in a minerals processing context where the specific gravity of the liquid (water) is taken to be one:






Then combining with the first equation:




Then since


we conclude that



\phi_{sl,v} is the solids fraction of the slurry on a volumetric basis
\phi_{sl,m} is the solids fraction of the slurry on a mass basis
M_{s} is the mass or mass flow of solids in the sample or stream
M_{sl} is the mass or mass flow of slurry in the sample or stream
M_{l} is the mass or mass flow of liquid in the sample or stream
SG_{s} is the bulk specific gravity of the solids

See also[edit]


  1. ^ Oxford English Dictionary 2nd ed.: Slurry
  2. ^ Shlumberger: Oilfield glossary
  3. ^ Rheonova : Measuring rheological propertis of settling slurries
  4. ^ Portland Cement Association: Controlled Low-Strength Material
  5. ^ Red Valve Company: Coal Slurry Pipeline
  6. ^ Rheonova : Measuring food bolus properties
  7. ^ Wills, B.A. and Napier-Munn, T.J, Wills' Mineral Processing Technology: an introduction to the practical aspects of ore treatment and mineral recovery, ISBN 978-0-7506-4450-1, Seventh Edition (2006), Elsevier, Great Britain

External links[edit]