Slurries

A slurry is a mixture in which solid particles are suspended in a liquid, typically water. The solids can range from fine powders to granules and often constitute a substantial fraction of the suspension. Slurries are designed to keep solids dispersed for processing or transport, but without excessive settling when held in motion. The term covers a wide range of materials, including mineral slurries, cement slurries, and agricultural slurries.

Common examples include cement slurry (cement powder suspended in water used in concrete production), coal slurry (coal fines in water transported in pipelines), ore and tailings slurries in mining, pigment slurries in paint manufacture, and ceramic slips used for casting.

Rheology and stability are defining properties: viscosity or apparent viscosity, density, solids content, and the tendency for particles to settle or form a sediment. Some slurries are shear-thinning; others are Newtonian. Additives such as dispersants, thickeners, and flocculants modify flow behavior and suspension stability. Paste, thickened tailings, and high-solids slurries have different handling characteristics than dilute slurries.

Handling and processing often involve pumping through pipelines, with equipment like slurry pumps, reactors, thickeners, and clarifiers. Slurry transport requires controlling abrasion, erosion, and corrosion; pipe materials and lining are important. In agriculture, slurry refers to animal waste diluted with water used as fertilizer and processed in storage tanks.

Safety and environmental considerations include containment of spills, dust and aerosol generation from well-dried solids, and management of pump wear, energy use, and wastewater treatment. Definitions vary by industry, but the core concept remains a suspension of solids in a liquid designed for transport or processing.