GB434352A - Improvements in or relating to froth flotation concentration processes - Google Patents

Abstract

434,352. Concentrating ores. TAPLIN, T. J., 6, Walpole Gardens, Strawberry Hill, Middlesex. Nov. 30, 1933, Nos. 33668/33 and 13294/34. [Class 82 (ii)] In order to ensure good contact between the air bubbles and the mineral particles in froth flotation concentration a vibratory movement is imparted to the pulp in addition to the normal movement produced in the aeration by agitation or by the direct introduction of air, the vibratory movement being produced by imparting vibration to an impermeable surface in contact with the pulp on one side only. The vibration may be of sonic or supersonic frequency and is preferably applied in a direction transverse to the general movement of the bubbles in the pulp. In the form shown in Fig. 1, air is introduced through a pipe 15 and a porous false bottom 14 to ore pulp in a cell 11 having an overflow lip 13 for the froth. An aperture 19 in one wall of the cell is closed by a rubber diaphragm 20 which is connected by washers and clamping nuts to a rod 24 united by a coupling 38 to a push rod 33 held by a spring 36 against a cam 30 which is rotated at a speed sufficient to vibrate the diaphragm 20 at a frequency of about 300 cycles per second. Alternatively the diaphragm 20 may be vibrated by an intermittently energized electromagnet. Fig. 3 shows a pneumatic flotation cell in which the vibratory movement of the pulp is effected by imparting vibrations to a liquid in a rubber bag 44 on the end of a pipe 45 depending into the pulp from above. The liquid in the bag is deaerated and a pump may be employed or the height of the pipe 45 may be made sufficient to maintain the liquid under superatmospheric pressure to prevent cavitation. In the form shown in Fig. 4, two pneumatic cells 50, 51 are located side by side with a compartment 52 between them, the partitions 53, 54 being thin enough to transmit vibrations. The compartment 52 is partly filled with water and a flexible diaphragm 57 is vibrated by cam mechanism or by means of an electromagnet and causes the water to vibrate, the vibrations being transmitted to the pulp in the cells 50, 51 through the partitions 53, 54. The compartment 52 may be closed at the top so that the water may be maintained under superatmospheric pressure. To prevent cavitation the vibrations may be periodically interrupted, for example when using an electromagnetic vibrator a relay device may be provided which interrupts the vibrator when the power required to effect the vibrations falls owing to cavitation. U.S.A. Specification 1,910,386 is referred to.