GB698240A - Aerating method and dual aerating flotation machine - Google Patents

Abstract

698,240. Froth-flotation apparatus. DEHN, S. G. (Mining Process & Patent Co.). Jan. 3. 1950, No. 144/50. Class 82(ii) A froth flotation cell having a feed inlet, a froth overflow and a control member for regulating the pulp discharge, is fitted with an aerating member providing an upper agitation zone adjacent and beneath the froth overflow and a lower agitation zone adjacent the bottom of the cell, the aerating member having a rotary impeller in each zone with its bottom surface in open contact with the pulp in the cell and a means for discharging aerating gas for mixing by the impeller with the pulp in each zone. In a battery of such cells, Fig. 1, flotation pulp is fed in through an inlet 62 to a feed compartment 12 where, together with some intermediate fractions which are overflowed from the cell C over the weir 63, it is fed through a conduit 22 to the lower impeller of the cell C. Aerating gas from a conduit 33 passes, down the hollow shaft 23 and into the cell via outlets 34...37. Additional aerating gas of the same or different kind or at a different pressure may be fed into the enclosure 40 via the pipe 47. Additional flotation reagent may be fed into the compartment 12 through the shaft 23 or the pipe 47. The upper impeller 31, which acts as a recirculator to prevent the formation of a high density zone beneath the froth zone, is situated just below the froth bed and has a hood 49. The froth and values are overflowed over weirs (not shown) in the side of the cell and the pulp passes over an adjustable weir 14 and through an opening 20 into a feed compartment where, mixed with some intermediate fractions overflowed from a weir 63 from the succeeding cell, it is passed through the conduit 22 to the impeller 30 of cell C<SP>1</SP>. The settled granular constitutents are blown directly from cell C to cell C<SP>1</SP> through submerged Verituri passages 17 by compressed air from a pipe 18. Similar treatment takes place in Cell C<SP>1</SP>, the slimes being discharged through an opening 66 and the settled granular constituents through a Venturi passage 17 into the final cell C'.