1. General

1.1 Evolution

Although decantation has always been used for clarifying drinking water, it wasn't until the beginning of the 20th century that the concentration of ores in high-capacity laundries made it necessary to separate large flows of solids and liquids in continuous operation. In 1906, Dorr installed a continuous liquid-solid decanter at a gold mine in South Dakota. The decanter consisted of a large circular tank, the sloping bottom of which was fitted with a slowly rotating scraper mechanism that carried the settled solids to the lower central point of the unit. These were discharged through a discharge orifice, without creating turbulence, so that a clear liquid overflowed the periphery of the tank. The process spread to virtually all mineral processing plants and a wide range...