Dimitry J. Cognevich Jr.
Engineering at Mason Smith Ave, Metairie, LA

4126551, Nov 21, 1978

Apr 8, 1977

5/785946

Dimitry J. Cognevich - Metairie LA

Freeport Minerals Company - New York NY

B01D 2104

210 83

An apparatus and method are provided for handling the problem of crud formation in solvent extraction equipment. "Crud" is the name commonly given to the thick interfacial layer of semi-floatable material that accumulates and interferes with many solvent extraction operations. The apparatus disclosed is used in combination with mixer-settler equipment, and it includes a rotatable shaft, a blade mounted on the shaft, apparatus for moving the shaft and blade across a plane parallel to the surface of the liquid inside a rectangular settler vessel, equipment for rotating the blade and shaft about the shaft's longitudinal axis, and a locking device for locking the blade into an extended or retracted position. The method disclosed provides for lowering the blade into the liquid periodically and slowly traversing the length of the settler vessel; moving the crud mass toward one end of the vessel and causing it to be compressed therein; rotating the shaft and blade which causes the compressed crud to flow over a high-level weir at the end of the vessel; locking the blade with both faces parallel to the settler's surface and returning it to its original position, or to any other convenient predetermined position, from which it can be subsequently lowered again below the liquid level to start another cycle. The invention is particularly applicable to the solvent extraction recovery of uranium from wet-process phosphoric acid.