Membrane washing apparatus for flotation device

A flotation device comprising:

• a tank to contain a slurry incorporating minerals to be extracted;
• an aerator to aerate the slurry within the tank and to produce a zone of mineralised froth above the slurry;
• a recovery launder to collect the mineralized froth and to direct said froth away from the tank;
• and
• a porous diffusion surface in direct contact with the froth being configured to diffuse a washing liquid into the froth zone and to progressively infuse the froth with wash water permeating through the porous diffusion surface without imparting any substantial kinetic energy to the froth.

A method of recovering minerals from a slurry contained in a tank forming part of a flotation device, said method comprising the steps of:

• aerating the slurry within the tank and thereby producing a zone of mineralized froth above the slurry;
• diffusing a washing liquid directly into the froth zone without imparting any substantial kinetic energy to the froth by means of a porous diffusion surface in direct contact with the froth such that washing liquid infused into the froth progressively washes out entrained gangue material;
• collecting the mineralised froth in a recovery launder;
• and
• directing said froth away from the tank via said launder.

A flotation device comprising:

• a tank to contain a slurry incorporating minerals to be extracted;
• aeration means to aerate the slurry within the tank and thereby produce a zone of mineralised froth above the slurry;
• a recovery launder to collect the mineralized froth and to direct said froth away from the tank;
• and
• at least one porous diffusion surface in direct contact with the froth configured for diffusing a washing liquid directly into the froth zone, whereby the washing liquid is introduced into the froth zone without imparting any substantial kinetic energy to the froth and does not collapse or decompose the froth as occurs with conventional spray bar or shower type washing arrangements.