A method and apparatus for the recovery of hydrophobic particles from a slurry comprised of water, the hydrophobic particles, and a hydrophilic component. Slurry is exposed to a gas stream to permit bubbles to adhere to the hydrophobic particles. The slurry generally flows vertically through a vessel at a velocity that maintains gas hold-up at least between 30 and 70% to maintain a bubbly flow without a slurry froth interface so that a portion of the water of the slurry, together with entrained gas bubbles attached to hydrophobic particles, flows out of the vessel with a portion of the water of the slurry and the hydrophilic component remaining in the vessel. Water from the slurry and gas bubbles attached to hydrophobic particles flowing through the vessel is discharged and collected for processing. A portion of the hydrophilic component is extracted as tailings for disposal or subsequent processing.

A method and apparatus for the recovery of hydrophobic particles from a slurry comprised of water, the hydrophobic particles, and a hydrophilic component. Slurry is exposed to a gas stream to permit bubbles to adhere to the hydrophobic particles. The slurry generally flows vertically through a vessel at a velocity that maintains gas hold-up at least between 30 and 70% to maintain a bubbly flow without a slurry froth interface so that a portion of the water of the slurry, together with entrained gas bubbles attached to hydrophobic particles, flows out of the vessel with a portion of the water of the slurry and the hydrophilic component remaining in the vessel. Water from the slurry and gas bubbles attached to hydrophobic particles flowing through the vessel is discharged and collected for processing. A portion of the hydrophilic component is extracted as tailings for disposal or subsequent processing.

A method of recovering particles from a liquid, a froth flotation apparatus, and a method of recovering particles in a flotation cell are disclosed. In an embodiment, the method comprises a technique of exposing the particles to first-size bubbles having a first predetermined size; the first-size bubbles adhering to the particles; and exposing the particles in a liquid, with the first-size bubbles adhering to the particles, to second-size bubbles having a second predetermined size, the second predetermined size being at least approximately ten times larger than the first predetermined size. The method further comprises the second-size bubbles adhering to the particles and engulfing the first-size bubbles on the particles; and using the second-size bubbles adhering to the particles to recover the particles from the liquid. In one embodiment a first surfactant is used to form the first-size bubbles, and a second surfactant is used to form the second-size bubbles.

A method of recovering particles from a liquid, a froth flotation apparatus, and a method of recovering particles in a flotation cell are disclosed. In an embodiment, the method comprises a technique of exposing the particles to first-size bubbles having a first predetermined size; the first-size bubbles adhering to the particles; and exposing the particles in a liquid, with the first-size bubbles adhering to the particles, to second-size bubbles having a second predetermined size, the second predetermined size being at least approximately ten times larger than the first predetermined size. The method further comprises the second-size bubbles adhering to the particles and engulfing the first-size bubbles on the particles; and using the second-size bubbles adhering to the particles to recover the particles from the liquid. In one embodiment a first surfactant is used to form the first-size bubbles, and a second surfactant is used to form the second-size bubbles.

A flotation line for treating mineral ore particles suspended in slurry is disclosed. The flotation line includes a rougher part with at least one rougher flotation cell from which overflow is arranged to flow directly into a cleaner flotation line; and a scavenger part with at least two scavenger flotation cells from which overflow is arranged to flow back into a rougher flotation cell, or into a regrinding step and then into a cleaner flotation line. Underflow from a last scavenger flotation cell is arranged to be removed from the flotation line as tailings. At least 75% of the flotation cells include a mechanical agitator including a system for introducing flotation gas into the flotation cell. At least one of the flotation cells of the flotation line includes a mechanical agitator including a microbubble generator for introducing microbubbles into the slurry.

A flotation line for treating mineral ore particles suspended in slurry is disclosed. The flotation line includes a rougher part with at least one rougher flotation cell from which overflow is arranged to flow directly into a cleaner flotation line; and a scavenger part with at least two scavenger flotation cells from which overflow is arranged to flow back into a rougher flotation cell, or into a regrinding step and then into a cleaner flotation line. Underflow from a last scavenger flotation cell is arranged to be removed from the flotation line as tailings. At least 75% of the flotation cells include a mechanical agitator including a system for introducing flotation gas into the flotation cell. At least one of the flotation cells of the flotation line includes a mechanical agitator including a microbubble generator for introducing microbubbles into the slurry.

The flotation apparatus includes a flotation vessel and a cover for closing an upwards open opening of the flotation vessel, wherein the cover and the flotation vessel limits a vessel space for receiving fluid, and an agitating means having a rotatable axis extending through a first aperture in the cover. The rotatable shaft is rotatable supported at a bearing housing outside the vessel space. A connection arrangement surrounds the rotatable shaft between the bearing housing and the cover.

The flotation apparatus includes a flotation vessel and a cover for closing an upwards open opening of the flotation vessel, wherein the cover and the flotation vessel limits a vessel space for receiving fluid, and an agitating means having a rotatable axis extending through a first aperture in the cover. The rotatable shaft is rotatable supported at a bearing housing outside the vessel space. A connection arrangement surrounds the rotatable shaft between the bearing housing and the cover.

The invention pertains to a process for separating mixtures of solids based on their densities. The present invention also relates to the use of a separating liquid (L) for separating plastic solids from metal-containing solids based on their densities, wherein the separating liquid (L) has a density d3 such that 1.5<d3<2.0; wherein the solids have a particle size ranging from 0.1 to 100 mm. The separating liquid (L) is preferably a fluorinated fluid.

A method of recovering particles from a liquid, a froth flotation apparatus, and a method of recovering particles in a flotation cell are disclosed. In an embodiment, the method comprises a technique of exposing the particles to first-size bubbles having a first predetermined size; the first-size bubbles adhering to the particles; and exposing the particles in a liquid, with the first-size bubbles adhering to the particles, to second-size bubbles having a second predetermined size, the second predetermined size being at least approximately ten times larger than the first predetermined size. The method further comprises the second-size bubbles adhering to the particles and engulfing the first-size bubbles on the particles; and using the second-size bubbles adhering to the particles to recover the particles from the liquid. In one embodiment a first surfactant is used to form the first-size bubbles, and a second surfactant is used to form the second-size bubbles.