Abstract: A method for separating a mixture of plastics of at least two components selected from the group consisting of polyethylene, polypropylene and a polystyrene, which comprises placing the mixture of plastics in a separation cell containing an aqueous liquid medium containing at least one wetting agent, and introducing gas bubbles into the cell thereby to cause the gas bubbles to selectively adhere to the surface of the polypropylene and/or polyethylene and float the polypropylene and/or polyethylene when the mixture of plastics comprises a polystyrene and polypropylene and/or polyethylene or to selectively adhere to the surface of the polypropylene and float the polypropylene when the mixture of plastics comprises polypropylene and polyethylene with the polypropylene and/or the polyethylene being recovered as a float and the polystyrene being recovered as a residue when the mixture of plastics comprises a polystyrene and polypropylene and/or polyethylene, and with the polypropylene being recovered as a float an

Abstract: A method of separating highly hydrophobic plastics from a plastics mixture comprising placing the plastics mixture in an aqueous liquid medium, keeping the aqueous liquid medium in an agitated state to disperse the plastics mixture whereby the plastics having a higher hydrophobicity float on the aqueous liquid medium surface, and removing the plastics floating on the surface of the aqueous liquid medium.

Abstract: A method for separating large-sized film-like plastics, such as polypropylene or polyvinyl chloride, which comprises placing the plastics in a separation tank containing an aqueous liquid medium and introducing gas bubbles into the tank thereby to cause the gas bubbles to adhere to the surface of the plastics. The buoyancy of the gas bubbles causes the plastics to rise to the medium surface. Addition of a flotation agent and/or a wetting agent further promotes the floating of the plastics.

Abstract: A method for the separation of a mixture of a polyester and a cellulose derivative comprising introducing gas bubbles into an aqueous liquid medium containing the mixture of the polyester and the cellulose derivative, optionally in the presence of at least one wetting agent and at least one flotation agent thereby separating the mixture by flotation into the polyester and the cellulose derivative.

Abstract: A method for separating a plastics-containing mixture comprising a lead alloy, a polyolefin, a polystyrene and ebonite, which comprises (1) separating the lead alloy from the mixture in a running liquid, with the lead alloy being recovered as a residue; (2) placing the resulting plastics mixture comprising the polyolefin, polystyrene and ebonite in a separation cell containing an aqueous liquid medium in the presence of a wetting agent; (3) introducing gas bubbles into the cell thereby to cause the gas bubbles to selectively adhere to the surface of the polyolefin and float the polyolefin, with the polyolefin being recovered as a float; (4) adding a flotation agent into the cell containing the resulting plastics mixture comprising the polystyrene and ebonite; and (5) introducing gas bubbbles into the cell thereby to cause the gas bubbles to selectively adhere to the surface of the polystyrene and float the polystyrene, with the polystyrene being recovered as a float and the ebonite being recovered as a residu

Abstract: A method for the separation of a mixture of a polyester and a cellulose derivative comprising introducing gas bubbles into an aqueous liquid medium containing the mixture of the polyester and the cellulose derivative, optionally in the presence of at least one wetting agent and at least one flotation agent thereby separating the mixture by flotation into the polyester and the cellulose derivative.

Abstract: A method for separating vinyl chloride from a mixture of vinyl chloride with other non-plastic substances such as sand and soil, metals, glass or rubbers which comprises introducing gas bubbles into a dispersion of the vinyl chloride mixture in an aqueous liquid medium such as water or salt water and containing a flotation agent such as pine oil thereby to float the vinyl chloride and collect it.

Abstract: A flotation method for sulfide ores in which, prior to sulfide ore flotation for effecting a mutual separation of the ore constituents, there is carried out a pre-treatment or conditioning step by applying d-c current to the sulfide ore slurry by means of an electrode in order to depress the floatability of certain of the ore constituents.

Abstract: In the flotation of oxide ores, a method of flotation characterized by applying d-c current to the oxide ore slurry as a pre-treatment prior to flotation.