Slurry

A slurry composed of glass beads in silicone oil flowing down an inclined plane

A slurry is a mixture of solids with specific gravity greater than 1 suspended in liquid, usually water. Most common use of slurry is as a mean of transportation of solids being the liquid a carrier that is pumped on a device like a centrifugal pump. The size of solid particles may vary from 1 micron up to hundred of milliliters. The solids may settle at certain transport velocity and the mixture can behave as Newtonian or non-Newtonian fluid. Depending on the mixture the slurry may be abrasive and corrosive.

Examples

Examples of slurries include:

Cement slurry, a mixture of cement, water, and assorted dry and liquid additives used in the petroleum and other industries^[1]^[2]
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^[3]
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^[4]
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^[5]
A mixture of epoxy glue and glass microspheres used as a filler compound around core materials in sandwich-structured composite airframes.

Calculations

Determining solids fraction

To determine the percent solids (or solids fraction) of a slurry from the density of the slurry, solids and liquid^[6]

\phi _{sl}={\frac {\rho _{s}(\rho _{sl}-\rho _{l})}{\rho _{sl}(\rho _{s}-\rho _{l})}}

where

\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: