Blog | What is slurry?

Slurry is a mixture of water with solids, in which the solids are not dissolved but occur as particles. Slurry pumping is the process of moving a liquid substance with a high concentration of solids from one location to another.

The weight of slurries

The weight of slurries depends on the density of its components and the concentration of solids in the liquid. Here are some factors to determine the weight of a slurry:

• The density of the liquid (usually water) and the solids (such as cement, sand, minerals, etc.) play an important role;
• Water has a density of about 1000 kg/m³, while solids such as cement and minerals can have much higher densities;
• The percentage of solids in the slurry determines how heavy the slurry is. A higher concentration of solids leads to a higher density and thus a heavier slurry.

Gradations in slurries

Class 1, this is a light slurry with a low specific gravity. The average diameter of the particle size is less than 400 microns. The properties are more fluid, flows easily and has a lower density. Used in applications where high fluidity is required, such as in agriculture for spreading manure slurry or in the food industry for fruit purees and juices.

Class 2, medium slurry  has a moderate concentration of solids. The average diameter of the particle size up to 5000 microns. The properties are the balance between fluidity and density. It flows reasonably well but can also retain some solid structure. Medium slurry is used in concrete mixtures for construction projects.

Class 3, heavy slurry had a high solids content and high specific gravity. You recognize this because of the higher density, less liquid and can be firm or pasty. For pumping class 3 slurries experience and expertise is required.

Examples of slurries

There are a lot of different slurries;

• Sand slurry, A sand slurry is a mixture of sand and water, often used in various construction, mining, and industrial applications. For pumping sand slurry high pipe philosophy is required to avoid settling of sand in the pipeline.
• Concrete slurry, a mixture of cement, water, sand and gravel;
• Bentonite slurry, used in tunneling and drilling operations;
• Tailings slurry, a mixture of water and finely ground rock remaining after the extraction of valuable minerals;
• Manure slurry, a blend of animal manure, grass, hay propping and water. For the pumping of manure slurry a pump with a cutter or large solids handling is required;
• Sludge slurry, a combination of water and solid waste from sewage treatment plants;
• Ash slurry, a mixture of water and fly ash from coal-fired power plant.

Examples of Gradations in Applications

Agriculture, we have two different slurries in the agriculture; thin manure slurry and thick manure slurry. Thin manure slurry is easy to pump and spread, it is used to spread on the fields as liquid fertilizer. Thick manure slurry is more concentrated, less water content and may be needed for specific soil enrichment.

Mining, in the mining applications are thin tailing slurries and thick ore slurries. Thin tailing slurries are used to transport waste products from processing facilities to tailing dams. Thick ore slurries are more concentrated, used to more efficiently transport valuable ore to processing facilities.

Construction, in the construction we have two kinds of slurries; sand and concrete slurry. The thin slurry is used for self-leveling floors and other applications where high fluidity is required. Thick concrete slurry is used for heavy structures such as foundations and dams, where strong and firm mixture is required.