Method and apparatus for concentration of minerals by froth flotation

A froth flotation apparatus for concentrating minerals by froth flotation of a slurry containing a mixture of mineral particles and gangue particles, said apparatus comprising:

• a) a flotation column defined by an outer wall and having a top portion, a bottom portion and a central portion, for providing generally vertical flow of the slurry in said column;
• b) slurry feed means for introducing the slurry into said flotation column in the lower half of the central portion thereof;
• c) bubble introducing means disposed in the bottom portion of said flotation column for generating bubbles of gas;
• d) froth overflow means disposed in the top portion of said flotation column including an outlet for discharging a froth fraction of the slurry;
• e) a plurality of vertically spaced tail ports disposed alternately on opposite sides of the central portion of said flotation column for discharging a non-float fraction of the slurry;
• and
• f) a single, fluid-impermeable baffle having at least two edges associated with each tail port, each of said baffles being angled upwardly with one edge of the baffle affixed to the outer wall of said flotation column below said tail port and the other edge of the baffle disposed within the area of vertical flow in the central portion of said flotation column, said baffles being of sufficient size to block the vertical flow in at least 50% of the horizontal cross-sectional area of said flotation column to thereby create a quiescent flow zone in the area of each tail port.