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To increase the amount of a dissolved substance by evaporation.
(mining engineering)
To separate ore or metal from its containing rock or earth.
The clean product recovered in froth flotation or other methods of mineral separation.



(in mining), a product of mineral dressing that is more suitable for use or further processing than the initial raw material. In most cases, direct use of the extracted rock or its metallurgical or chemical processing is economically unfeasible and sometimes even technically impossible. A concentrate may have a high content of a valuable component (such as a metal), a small quantity of impurities (for example, iron and titanium in glass sand), or the required size (graded anthracite).

The quality of concentrates is regulated by government standards or by technical specifications that determine the size and the content of valuable components, undesirable impurities, and moisture. For example, concentrate must contain Pb > 70 percent, SiO2 < 2 percent, Cu < 1.5 percent, Zn < 2.5 percent, and Fe < 8 percent for lead hearth smelting and Pb > 30 percent, Cu < 4 percent, and Zn < 12 percent for shaft smelting.

A distinction is made among preconcentrate (coarse or crude concentrate), which is subjected to further dressing; bulk concentrate, which contains several valuable components; and final concentrate. In most cases, concentrate is a raw material for metallurgical, chemical, and other production processes.

References in periodicals archive ?
Though Donaldson himself does occasionally mention some of the uncanonical plays, he follows the fashion of concentrating upon The Alchemist and Volpone.
American novelist and short-story writer whose near-autobiographical fiction avoids plot, instead concentrating upon careful, close description of feeling.
His edition, concentrating upon text, is to be published posthumously, following the further death of his continuator, Paulinus Bellet.
Included in the therapies also are heat, oxygen, poultices, vibrations, pressure, hypnosis and mental diversion (not concentrating upon pain).
At this stage the company is concentrating upon the performance aspects of the sportster and is refraining from releasing details of likely economy and emissions although it is expected to be added to Audi's production portfolio of impressive European oil-burners in due course.