Patent EA-003898-B1 (EA)
Title: Flotation mechanism and method for dispersing gas and controlling flow in a flotation cell
Inventor: JOUNELA SEPPO
IPC: B03D1/16
Filed: 2001-07-19
Abstract: 1. A flotation mechanism for use in a flotation cell, characterized in that the flotation mechanism (4) is comprised of a directional element (25) suspended from the bottom end of a hollow shaft (3) which extends into the lower section of the cell, and upright vanes (26) attached inwards from the substantially outer edge, extending above and below the directional element, and that an substantially horizontal circular plate (27) of the directional element (25) is attached at the center symmetrically around the shaft and that the outer edge of the central plate is inclined downwards to form a guiding lap (28). 2. A flotation mechanism according to claim 1, characterized in that the downward inclined lap (28) of the directional element forms a 30-60 degree angle with the horizontal. 3. A flotation mechanism according to claim 1, characterized in that the diameter of the directional element lap (28) is [1/2]-[1/6] times that of the whole directional element. 4. A flotation mechanism according to claim 1, characterized in that the width of the upright vanes (26) is greater than that of the directional element lap (28). 5. A flotation mechanism according to claim 1, characterized in that the upright vanes (26) are attached radially to the directional element (25). 6. A flotation mechanism according to claim 1, characterized in that an outer edge (30) of the upright vanes is vertical and an inner edge (29) is vertical at the top and narrowing in an outward curve at the bottom (31). 7. A flotation mechanism according to claim 6, characterized in that the curve of the bottom (31) of the inner edge of the upright vane follows the shape of a circular arc, where the center point of the circle is on the outer edge of the vane. 8. A flotation mechanism according to claim 1, characterized in that a gas guiding plate (33) is placed on the inside of the directional element lap (28). 9. A flotation mechanism according to claim 8, characterized in that the diameter of the gas guiding plate (33) is between that of the circular plate (27) and that of the mixing mechanism shaft (3). 10. A flotation mechanism according to claim 8, characterized in that the distance of the guiding plate (33) from the circular plate (27) is between [1/2]-[1/6] times the diameter of the mixing mechanism shaft (3). 11. A flotation mechanism according to claim 1, characterized in that the flotation mechanism is located in a flotation cell (2, 20), which is equipped with vertical and horizontal flow guiding elements (13, 9). 12. A flotation mechanism according to claim 1, characterized in that a stator (5) is placed in the flotation cell (2, 20) around the flotation mechanism (4). 13. A flotation mechanism according to claim 1, characterized in that the hollow shaft (3) of the flotation mechanism (4) acts as a gas feed device. 14. A method for mixing gas into a mineral slurry and preventing sanding in a flotation cell, whereby a powerful agitation is achieved in a mixing zone (I) of the flotation cell, which assists in directing the slurry suspension formed towards the side walls of the cell, where the flow is diverted back towards the middle of the cell, from where the suspension flow containing mineral flakes attached to bubbles of gas rises from around the central axle of the cell in a concentration zone (II) to an attenuation zone (III), where the flow is diverted from the center of the cell towards the sides and the froth which is generated is removed from a froth layer (IV), characterized in that gas is fed into the mineral slurry in the mixing zone (I) through the hollow shaft of the flotation mechanism under said mechanism and dispersed into the mineral slurry; the direction of the slurry suspension is altered by a directional element (25), cylindrically inclined downwards from the outer edge, in a downward slanting direction towards the side walls of the flotation cell. 15. A method according to claim 14, characterized in that the direction of the gas is changed to horizontal, before it is dispersed into the mineral slurry.