Method for separating low density particles from feed slurries

A method of separating particles from feed slurries, said method comprising:

• feeding the feed slurry into a feed box having a plurality of hollow porous parallel plates such that the feed slurry flows between the hollow porous parallel plates;
• feeding a gas into at least one of the hollow porous parallel plates;
• allowing the gas and the slurry to mix within the feed box and discharge as a bubbly mixture from a discharge end of the feed box into a separation chamber, wherein the separation chamber has an upper region, a lower region, an upper end defining an upper boundary of the upper region, and a lower end defining a lower boundary of the lower region;
• forming a fluidized bed of bubbles from the discharged bubbly mixture in the separation chamber above a plurality of inclined channels located in the lower region of the separation chamber;
• allowing the bubbly mixture to flow through the separation chamber and into the inclined channels such that some of the particles escape the bubbly mixture flow and slide up the downwardly facing inclined surfaces of the inclined channels while other particles in the bubbly mixture travel down the channels;
• removing said some of the particles from the separation chamber through a first outlet arranged in the separation chamber and located above both the inclined channels and the discharge of the feed box;
• and
• removing the other particles from the separation chamber at a controlled rate through a second outlet arranged in the separation chamber and located below both the inclined channels and the discharge of the feed box.

A method of separating particles from feed slurries, said method comprising the steps of:

• feeding the feed slurry into a conduit;
• feeding a gas into the conduit;
• allowing the gas and the slurry to mix within the conduit and discharge as a bubbly mixture from a discharge end of the conduit into a separation chamber, wherein the separation chamber has an upper region, a lower region, an upper end defining an upper boundary of the upper region, and a lower end defining a lower boundary of the lower region;
• forcing wash water under pressure through the upper end and into the upper region of the separation chamber such that the wash water directly engages concentrated suspensions of particles within the upper region of the separation chamber at the upper end;
• forming a fluidized bed of bubbles from the discharged bubbly mixture in the separation chamber above a plurality of inclined channels located in the lower region of the separation chamber,
• allowing the bubbly mixture to flow through the separation chamber and into the inclined channels such that some particles escape the downward bubbly mixture flow and slide up the downwardly facing inclined surfaces of the inclined channels while other particles in the bubbly mixture travel down the inclined channels;
• removing the concentrated suspensions of particles from the upper region of the separation chamber through a first outlet arranged in the separation chamber and located above both the inclined channels and the discharge end of the conduit, and
• removing the other particles from the separation chamber at a controlled rate through a second outlet arranged in the separation chamber and located below both the inclined channels and the discharge end of the conduit.