A flotation tank has an input to receive a slurry from a pipeline section. The slurry contains finer mineral particles and coarser mineral particles. The pipeline section has one or more loops or coiled sections arranged to perform partial centrifugal separation on the finer and coarser mineral particles. As the mineral particles are moved tangentially into the lower part of the flotation tank, the coarser mineral particles tend to be near the tank wall while the finer mineral particles tend to move into the central part of the tank. Air bubbles or lightweight synthetic bubbles are used to collect and lift the finer mineral particles to the upper part of the tank. The coarser mineral particles are recovered by using collection surfaces coated with a hydrophobic material.

A system for recovery of animal byproducts and providing water reuse from an animal processing plant waste stream. In one embodiment of the invention there is an equalization tank forming part of an animal processing plant that is mechanically filtered to recover animal byproducts from a water mixture in the equalization tank. In another aspect of the invention there is a skimmer tank that contains a skimmer mixture with water and animal byproducts. The system mechanically separates the animal byproducts from the skimmer mixture in a manner that is suitable for human consumption. The system also allows the separated water to be reused in the animal processing plant.

An apparatus, such as a compact flotation unit, may include a tank having a fluid inlet. A cylinder may be disposed within the tank and have an open end. A first guide vane may be disposed about the cylinder, with the first guide vane having a portion axially aligned with the fluid inlet. A second guide vane may be disposed about the cylinder adjacent the open end thereof and may include a first end and a second end, with the first end of the second guide vane being axially offset from the second end of the second guide vane.

A froth flotation apparatus including a tank defining an interior, for holding a slurry, an aerator for aerating a mineral feed stream entering the interior and a system for feeding the aerated mineral stream into a contactor located in the tank.

The present invention comprises a process and apparatus for separation of hydrocarbons from hydrocarbon-containing produced water, wherein in stage 1 the hydrocarbon-containing produced water is supplied with a gas-containing component, whereupon a gas- and hydrocarbon-containing produced water mixture is fed to an inlet tube (22, 27) in the center of a tank, whereupon the said mixture is tangentially distributed via at least one nozzle (7) and at least one baffle plate (8.1), whereupon separated hydrocarbons are conveyed to at least one outlet from the tank and cleaned water is conveyed to an outlet (12) from the tank.

Several agitators for generating a mixture are described which generally have a housing and an impeller rotatably mounted within the housing. The impeller has a first end with a first end face, and plurality of protuberances and at least one compressed gas channel outlet disposed on the first end face. The agitator also has a mixing chamber that is located adjacent to the plurality of protuberances, a fluid inlet extending through the housing for supplying a mixing fluid to the mixing chamber, and a fluid outlet extending through the housing for discharging the mixture from mixing chamber. When the compressed gas and the mixing fluid are supplied to the mixing chamber, the compressed gas becomes uncompressed gas, and rotation of the impeller agitates the uncompressed gas and the mixing fluid and disperses the uncompressed gas and at least a portion of the mixing fluid to generate the mixture.

A method of removing metal particles from a contaminated metalworking fluid comprising emulsion droplets and metal particles includes pressurizing a first clean metalworking fluid with gas to provide an aerated metalworking fluid; releasing the pressure of the aerated metalworking fluid to form a plurality of bubbles; applying a shear force to the contaminated metalworking fluid to separate the emulsion droplets from the metal particles; flowing the contaminated metalworking fluid with the aerated metalworking fluid in a laminar flow to form a combined fluid, wherein the flowing occurs during the formation of the plurality of bubbles and while the emulsion droplets are separated from the metal particles, and wherein the laminar flow lasts for a time sufficient for the plurality of bubbles to attach to the metal particles; releasing the combined fluid into a flotation tank; and removing the metal particles to form a second clean metalworking fluid.

A method of removing metal particles from a contaminated metalworking fluid comprising emulsion droplets and metal particles includes pressurizing a first clean metalworking fluid with gas to provide an aerated metalworking fluid; releasing the pressure of the aerated metalworking fluid to form a plurality of bubbles; applying a shear force to the contaminated metalworking fluid to separate the emulsion droplets from the metal particles; flowing the contaminated metalworking fluid with the aerated metalworking fluid in a laminar flow to form a combined fluid, wherein the flowing occurs during the formation of the plurality of bubbles and while the emulsion droplets are separated from the metal particles, and wherein the laminar flow lasts for a time sufficient for the plurality of bubbles to attach to the metal particles; releasing the combined fluid into a flotation tank; and removing the metal particles to form a second clean metalworking fluid.

A separation system is disclosed for separating selected particles from a mixture of particles in a fluid. The system includes a froth flotation vessel 10 into which in use the mixture of particles and fluid are subjected to an upward flow of an introduced gas to form a froth layer 13 which rises above an interface 14 formed between the froth layer 13 and the mixture of particles and fluid 12, such that a quantity of the selected particles is conveyed out of the vessel 10 by the froth layer 13 to become a first product of the system. The vessel 10 also has a first outlet 29 arranged in use for receiving a flow of some of the mixture of particles and fluid from the vessel 10, an entry to the first outlet 29 being located in a region proximate to, but below, the interface 14. The vessel also has a second outlet 20 arranged in use for receiving a flow of some of the mixture of particles and fluid from a region of the vessel 10 which is located below the first outlet 29. In use the first outlet 29 receives a quantity of the selected particles which were not conveyed out of the vessel by the froth layer 13, and the second outlet 20 receives a quantity of the selected particles in a first by-product of the system. The first by-product comprises a relatively higher percentage of solids compared to the flow of particles and fluid in the first outlet 29. The flow of the mixture of particles and fluid from the vessel 10 via the first outlet 29 passes to a classification device 31, 76 which separates the flow into two or more fractions on the basis of their size or density or a combination of the two.

Separation of hydrophobic particles from a mixture of particles in a fluid is performed by providing a fluidized bed as a relatively non-turbulent contacting mechanism in a flotation cell incorporating a settling chamber located immediately above the fluidized bed. Hydrophobic particles attach to bubbles in the fluidized bed and rise to the interface with the settling chamber where non-hydrophobic particles flow over the lip of an internal launder and are removed as tailings at. The hydrophobic particles attached to bubbles float upwardly in the relatively placid settling chamber where unwanted gangue can fall back to interface. The bubbles form a froth layer at the upper surface of the settling chamber, and flow over the launder lip carrying the hydrophobic particles. An operation of the apparatus is kept stable by recirculating fluid from the settling chamber via pip and pump to mix with new feed entering at duct.