Ube Industries, Inc.

Osaka University

Shigehiro Nishijima

Fumihito Mishima

Toshihiro Shimakawa

Koji Kaiso

The present invention is a method for applying a gradient magnetic field to a paramagnetic supporting liquid containing a mixture of first particles and second particles to separate the mixture by particle type. A magnetic susceptibility of the first particles is lower than that of the liquid, and a magnetic susceptibility of the second particles is higher than that of the liquid. A gradient magnetic field is applied to the liquid in a separation tank provided with a magnetic filter and the liquid is stirred. The first particles float in the liquid by a magneto-Archimedes effect. A horizontal magnetic force acts on the first particles by the gradient magnetic field, so that the first particles travel to a region lateral to or outward from the magnetic filter and are gathered in the region. The magnetic filter is excited by the gradient magnetic field to catch the second particles.

Method and apparatus for separation of mixture

The present invention provides a method and an apparatus for separating a mixture that are capable of separating a mixture containing a plurality types of particles, using a countercurrent classification technique, even when there is little difference in density and particle diameter depending on the types of particles. In the present invention, a mixture containing first particles and second particles is separated using a separation tubehaving the inverted-conical or pyramidal shape or a substantially inverted-conical or pyramidal shape. The first particles and the second particles are made of substances having different magnetic susceptibilities. A fluid is caused to flow upward through the separation tube, and the flow of the fluid is used to introduce the mixture into the separation tube. The first particles and the second particles are held in the separation tubein a mixed state. A gradient magnetic field is applied to a region inside the separation tubeusing magnetic field generation means, in the state where the first particles and the second particles are held in the separation tube. The magnetic field gradient of the gradient magnetic field has a vertical component.

The present invention provides a method and an apparatus capable of continuously and accurately separating, by type, a mixture containing at least two types of particles, or capable of separating specific particles from the mixture, using a gradient magnetic field. In the present invention, a mixture containing at least two types of particles, particles of one type of which are made of a paramagnetic or diamagnetic substance, is treated. A magnetic field whose magnetic field gradient has a vertical component and a horizontal component is applied to a supporting liquidstored in a separating tank. When the mixture is placed into the supporting liquid, the particles of the one type are guided such that they are positioned in the supporting liquidat a predetermined height from a bottom faceof the separating tankwhile horizontally traveling. Alternatively, the particles of the one type magnetically levitate at a liquid surface of the supporting liquidand horizontally travel. Particles of another type of the at least two types of particles are positioned at a position vertically different from that of the particles of the one type, between the bottom faceof the separating tankand the liquid surface of the supporting liquid

Provided are a mixture separation method and a separation apparatus in which agglomeration of particles contained in the mixture is suppressed, energy required in distillation treatment of a supporting liquid is small in comparison with conventional methods, and particles that cannot be separated by conventional methods can be separated from a mixture containing the particles. The separation method and separation apparatus of the present invention separate, by type, a plurality of types of particles formed of mutually different materials by applying a magnetic field having a magnetic field gradient to the mixture containing the plurality of types of particles in the supporting liquid. Alternatively, the separation method and separation apparatus of the present invention separate a specific type of particle from such mixture. The supporting liquid is an organic solvent solution obtained by dissolving one or more types of paramagnetic compounds in an organic solvent. The plurality of types of particles includes particles of an inorganic salt, an organic acid salt, an inorganic oxide or a macromolecular compound. The organic solvent may be selected from the group consisting of alcohols, ethers, nitriles, ketones, esters, amides, sulfoxides, halomethanes and hydrocarbon solvents.

The processing method for a mixture according to the present invention is a method for processing a mixture having first particles made of a magnetic material or a nonmagnetic material and second particles made of a magnetic material or a nonmagnetic material wherein the second particles are mixed in a fluid medium containing the first particles, and comprises a dispersion step of dispersing aggregates of the first particles and the second particles present in the mixture, and a magnetic separation step of providing the first particles and second particles with a magnetic force a of different magnitudes by applying a magnetic field to the mixture in parallel with or after the dispersion step, thereby separating the first particles and the second particles from each other.

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Osaka, Japan

Shigehiro Nishijima