An apparatus for separating by froth flotation hydro- phobic and hydrophilic particles contained in an aqueous slurry, the apparatus comprising a generally vertical tubular column having an upper froth zone, an upper separation zone, a lower separation zone, an air inlet zone, and an intermediate feed inlet zone; a feed inlet, air inlet, froth outlet and a tailings outlet; an upper baffle unit comprising a plurality of horizontally extending upper baffle plates, a vertical upper support member including an upper end portion, and first upper apparatus for removably mounting the upper baffle plates on the upper support member at predetermined vertically spaced positions; each of the upper baffle plates comprising a mounting aperture and a plurality of flow apertures; and a second upper apparatus for removably supporting the upper support member in the column with the upper baffle plates in the upper separation zone. The apparatus can include a lower baffle unit. The open area of each baffle plate and the vertical space between adjacent baffle plates can vary between different baffle plates in dependence upon the position of a baffle plate in the column, or in dependence upon one or more of the following: a solids flow rate at the position, a liquid flow rate at the position, and a gas flow rate at the position. The invention also provides a method for improving the operating performance of an unbaffled column.https://digitalcommons.mtu.edu/patents/1076/thumbnail.jp
