Deep-shaft flotation

Wang, L.K. Preliminary Design Report of a 10-MGD Deep Shaft-Flotation Plant for the City of Bangor, PB88-200597/AS U.S. Department of Commerce, National Technical Information Service Springfield, VA, 1987 42 p. 

The aeration requirements of the deep shaft (vertical shaft bioreactor using flotation technology) are provided by two, 100 hp rotary screw compressors rated at a pressure of 7 kg/m2 (100 psig). Dissolved oxygen (DO) levels of 4 mg/L are maintained in the head tank, and during the startup phase of the plant a DO meter measured a dissolved oxygen concentration of 25 mg/L at the shaft bottom. 

Spodumene had been produced from the Preissac-Lacorne deposit by the Quebec Lithium Corp. from 1955 to 1959, supplying ore to LCA s North Carolina plant. Mining was conducted underground, with the initial area developed about 450 m in diameter from a 171 m deep shaft. After mining, the ore was concentrated by flotation (Kesler, 1960) in a mill near the shaft site with a capacity of 2000 mt/day of concentrates. This operation closed when LCA opened their own mine in North Carolina (Kunasz, 1994). 

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