An apparatus for the wet attrition of particulate material comprising an attrition scrubber; a dewatering screen comprising a deck and a sump beneath the deck, the dewatering screen being mounted upstream of the attrition scrubber whereby oversize material from a downstream end of the deck of the dewatering screen passes into the attrition scrubber; and a hydrocyclone wherein an underflow, containing a coarser fraction of the feed slurry, passes out of a lower outlet of the hydrocylone while an overflow, containing a finer fraction of the feed slurry and most of the water, passes out of an outlet at the upper end of the hydrocyclone, a pump being provided for pumping material from the sump of the dewatering screen to the inlet of the hydrocyclone, wherein the underflow from the hydrocyclone is passed into the attrition scrubber.

An apparatus for the wet attrition of particulate material comprising an attrition scrubber; a dewatering screen comprising a deck and a sump beneath the deck, the dewatering screen being mounted upstream of the attrition scrubber whereby oversize material from a downstream end of the deck of the dewatering screen passes into the attrition scrubber; and a hydrocyclone wherein an underflow, containing a coarser fraction of the feed slurry, passes out of a lower outlet of the hydrocylone while an overflow, containing a finer fraction of the feed slurry and most of the water, passes out of an outlet at the upper end of the hydrocyclone, a pump being provided for pumping material from the sump of the dewatering screen to the inlet of the hydrocyclone, wherein the underflow from the hydrocyclone is passed into the attrition scrubber.

A substrate for use in an aqueous slurry has a polymeric coating to provide a compliant and sticky surface. The polymer coating has a chemical to render the surface hydrophobic so as to attract hydrophobic or hydrophobized mineral particles in the slurry. The surface has a surface roughness structure in the nano-scale to micro-scale range. The substrate can take the form of a conveyor belt, a bead, a mesh, an impeller, a filter or a flat surface. The substrate can also be an open-cell foam. The polymeric coating can be modified with tackifiers; plasticizers; crosslinking agents; chain transfer agents; chain extenders; adhesion promoters; aryl or alky copolymers; fluorinated copolymers and/or additives; hydrophobicizing agents such as hexamethyldisilazane; inorganic particles such as silica, hydrophobic silica, and/or fumed hydrophobic silica; MQ resin; and/or other additives to control and modify the properties of the polymer.

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.

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.

What is claimed is a flotation separation system for partitioning a slurry. The slurry includes a hydrophobic species that can adhere to gas bubbles that form within the slurry. The flotation separation system includes a flotation separation cell. The flotation separation cell has a sparger unit and a separation tank. The separation tank is constructed to allow the bubble dispersion to form a froth at the top of the slurry contained in the separation tank. The sparger unit includes a slurry inlet, a slurry outlet, a sparging mechanism, a high shear element, and a gas inlet.

What is claimed is a flotation separation system for partitioning a slurry. The slurry includes a hydrophobic species that can adhere to gas bubbles that form within the slurry. The flotation separation system includes a flotation separation cell. The flotation separation cell has a sparger unit and a separation tank. The separation tank is constructed to allow the bubble dispersion to form a froth at the top of the slurry contained in the separation tank. The sparger unit includes a slurry inlet, a slurry outlet, a sparging mechanism, a high shear element, and a gas inlet.

A method and apparatus is disclosed for separating an amount of an amphiphilic contaminant substance such as PFAS from water. The method comprising the steps of admitting the water which contains the substance into a flotation cell chamber, and then introducing a flow of gas thereinto. The gas is introduced by several different apparatus options for efficient aeration of the chamber, depending on the water being treated. The introduced gas produces a froth layer which is formed at, and which rises above, an interface with the contents of the chamber. The froth layer includes an amount of water and also a concentrated amount of the contaminant substance when compared with its initial concentration. The process then involves collapsing and removing the froth layer, with several options for removing the PFAS from that liquid by re-flotation to reconcentrate the PFAS, or absorption onto a solid substrate material. The treated water an also pass out of the chamber through an absorptive treatment device to remove an amount of the substance not already recovered in the foamate.