Froth zone characterisation of an industrial flotation column in rougher circuit.

The froth zone of a rougher column at the Miduk copper concentrator in Iran was studied. The solids and grade profiles along the froth zone indicated that most of the upgrading took place just above the interface where major loss of the bubble surface occurred. A considerable proportion of the feed water reported to the concentrate, particularly at higher gas velocities, indicating that the rougher columns represented a compromise between grade and recovery. The overall flotation rate constant increased nearly linearly with bubble surface area flux for shallow and intermediate froth depths but deviated from linearity at higher froth depths, indicating that mass transfer from the collection to the froth zone is rate-limiting at shallow froth depths and that transfer from the froth over the cell lip is rate-limiting at greater froth depths. Equations are presented showing the relationships between overall rate constant, froth depth and gas velocity; froth recovery and froth residence time; and overall rate constant, bubble surface area flux and slurry froth residence time.
The froth zone of a rougher column at the Miduk copper concentrator in Iran was studied. The solids and grade profiles along the froth zone indicated that most of the upgrading took place just above the interface where major loss of the bubble surface occurred. A considerable proportion of the feed water reported to the concentrate, particularly at higher gas velocities, indicating that the rougher columns represented a compromise between grade and recovery. The overall flotation rate constant increased nearly linearly with bubble surface area flux for shallow and intermediate froth depths but deviated from linearity at higher froth depths, indicating that mass transfer from the collection to the froth zone is rate-limiting at shallow froth depths and that transfer from the froth over the cell lip is rate-limiting at greater froth depths. Equations are presented showing the relationships between overall rate constant, froth depth and gas velocity; froth recovery and froth residence time; and overall rate constant, bubble surface area flux and slurry froth residence time.