What is Slurry?
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Slurry is a watery mixture of an insoluble matter. In the mining industry, slurry pumps are used to transport slurries in many applications around the world.

Dredging, for instance, involves the largest quantities: harbors and rivers are dredged continually to maintain navigation; coastlines are altered; and material is needed for landfill and construction purposes. Very large centrifugal pumps are used, because a single dredge may be required to maintain a throughput of 7,000 tons of slurry per hour or more at flows of 60,000 to 80,000 gallons per minute (13.600 to 18.000 cubic meters per hour).

The manufacture of fertilizer is another application that involves massive slurry transport operations. In Florida, phosphate matrix is recovered by huge draglines in open-pit mining operations. It is then slurried (mixed with water) and pumped to the wash plant through pipelines with a typical length of about six miles.

Each year, 34 million tons of matrix are transported in this manner.

This industry uses centrifugal pumps that are generally smaller than those used on large dredges, but impeller diameters up to 54 inches (1.370 millimeters) are common and drive capacity is often in excess of 1,500 horsepower (1.120 kilowatt hours). The transport distance is typically longer than that of dredging applications and a series of five or six pumping stations is often used.

Many other types of open-pit mining use slurry transport and the number of such applications is increasing. Syncrude, the world's largest producer of crude oil from oil sands, has refined hydrotransport technology for mining oil sands. In this new process, the oil sands are made into a slurry and transported to the processing plant via pipelines rather than on the traditional and more expensive conveyor belts.

A somewhat unusual application is the transport of a slurry of salt in brine. Salt water is taken from the bay and moved through various evaporation ponds to promote growth of the salt crystals. The product of this process is collected in a slurry pit and then transported through pumps to washing and storage facilities.

Partially processed material from mining and metallurgical operations and other industries is often already in slurry forms. For example, slurry pumps are required to move coal, which is in slurry form, through the washing process. The process removes impurities and upgrades the heating value of the coal.