Abstract: The invention relates to a mixing device and method by means of which two solutions that are insoluble or poorly soluble in each other are mixed together into a dispersion. The device consists of at least three helical bars rotating upwards around a shaft and supported on it, so that the support structures between the shaft and the helical rods are set essentially in a horizontal position. The device and method are particularly suitable for mixing solvent extraction solutions used in the hydrometallurgical recovery of metals to form a dispersion.

Abstract: The invention relates to a turbine-type high-power impeller, to be used for mixing slurry in hydrometallurgical process reactors. The impeller is formed of at least five blades, each of which blades comprises a front edge, trailing edge, root and tip; the roots of the impeller blades are permanently attached by a joint to the hub or axis of the impeller, so that the front edge of the impeller blade is straight, and the trailing edge is chamfered, in which case the blade is narrowed towards the tip, and the blade is provided with two longitudinal folds arranged in parallel with the front edge of the blade.

Abstract: A method and apparatus for converting an iron-bearing residue generated in a hydrometallurgical process that contains small amounts of soluble heavy metals into a stable form by means of a neutralizing agent. The residue is elutriated and the elutriated residue is fed into at least one stabilization or homogenization reactor, into which a neutralizing agent is also routed, and the homogenous mixing together of the residue and neutralizing agent takes place by means of a helix mixer, where the ratio of the diameter of the mixer to the diameter of the reactor is 0.75-0.99.

Abstract: A method and arrangement for separating two solutions mixed in dispersion into two solution phases in a liquid-liquid extraction separation cell. A lighter solution phase placed on the heavier solution phase is forced to flow as a thin overflow layer over the top edge of a front panel such that the dispersion thickens A rear panel is essentially parallel with the front panel so that in between the front panel and the rear panel, there is formed an uptake shaft along which the thickened dispersion can rise and be compressed.

Abstract: The invention relates to an apparatus and method for removing molybdenum and other possible impurities from an organic copper-containing extraction solution in connection with the liquid-liquid extraction related to copper recovery. The removal of impurities occurs in one or several removal units built into the organic extraction solution storage tank.

Abstract: A method for the selective recovery of uranium from a sulphate-based acidic aqueous solution of uranium containing iron and other metals by means of solvent extraction, in which the extractant used in the organic extraction solution is bis(2-ethylhexyl) phosphate and a liquid branched trialkyl phosphine oxide is the modifying agent. It is typical of the method that the uranium concentration in the feed solution is less than 50 mg/l and a reducing agent is introduced into the aqueous and/or extraction solution to prevent the permanent oxidation of iron to trivalent. In the method the majority of the extraction solution is circulated in a circuit consisting of the extraction stage and the storage tank and only a small part of the uranium-loaded extraction solution is routed to scrubbing and stripping.

Abstract: The invention relates to a method and arrangement for separating two solutions mixed in dispersion into two solution phases in a liquid-liquid extraction separation cell. The arrangement includes a first guide wall extending along the whole width of the cell with respect to the vertical direction at an inclined angle. The first guide wall includes a bottom edge, which is located at a distance from the cell bottom, so that a clearance gap is formed between the bottom edge and the cell bottom. The arrangement also includes a second guide wall essentially parallel with the first guide wall and placed at a distance therefrom. Between the first guide wall and the second guide wall an uptake shaft is formed extending diagonally upwards at the inclined angle. The second guide wall is pressed tightly against the cell bottom, and includes a number of vertical slots.

Abstract: The invention relates to a mixing device and method by means of which two solutions that are insoluble or poorly soluble in each other are mixed together into a dispersion. The device consists of at least three helical bars rotating upwards around a shaft and supported on it, so that the support structures between the shaft and the helical rods are set essentially in a horizontal position. The device and method are particularly suitable for mixing solvent extraction solutions used in the hydrometallurgical recovery of metals to form a dispersion.

Abstract: A method and apparatus for converting an iron-bearing residue generated in a hydrometallurgical process that contains small amounts of soluble heavy metals into a stable form by means of a neutralising agent. The residue is elutriated and the elutriated residue is fed into at least one stabilisation or homogenisation reactor, into which a neutralising agent is also routed, and the homogenous mixing together of the residue and neutralising agent takes place by means of a helix mixer, where the ratio of the diameter of the mixer to the diameter of the reactor is 0.75-0.99.

Abstract: A method for the selective recovery of uranium from a sulphate-based acidic aqueous solution of uranium containing iron and other metals by means of solvent extraction, in which the extractant used in the organic extraction solution is bis(2-ethylhexyl) phosphate and a liquid branched trialkyl phosphine oxide is the modifying agent. It is typical of the method that the uranium concentration in the feed solution is less than 50 mg/l and a reducing agent is introduced into the aqueous and/or extraction solution to prevent the permanent oxidation of iron to trivalent. In the method the majority of the extraction solution is circulated in a circuit consisting of the extraction stage and the storage tank and only a small part of the uranium-loaded extraction solution is routed to scrubbing and stripping.

Abstract: The invention relates to a mixing reactor for mixing a liquid and pulverous solid, clarification the solution that is formed and discharging the clarified solution from the mixing reactor, in the lower section of which a fluidized bed is formed. The invention also relates to a method for mixing a liquid and pulverous solid into each other in a fluidized bed, for clarification the solution that is formed and for discharging the clarified solution from the mixing reactor.

Abstract: The invention relates to a turbine-type high-power impeller, to be used for mixing slurry in hydrometallurgical process reactors. The impeller is formed of at least five blades, each of which blades comprises a front edge, trailing edge, root and tip; the roots of the impeller blades are permanently attached by a joint to the hub or axis of the impeller, so that the front edge of the impeller blade is straight, and the trailing edge is chamfered, in which case the blade is narrowed towards the tip, and the blade is provided with two longitudinal folds arranged in parallel with the front edge of the blade.

Abstract: The invention relates to an apparatus and method for removing molybdenum and other possible impurities from an organic copper-containing extraction solution in connection with the liquid-liquid extraction related to copper recovery. The removal of impurities occurs in one or several removal units built into the organic extraction solution storage tank.

Abstract: The invention relates to a method and arrangement for separating two solutions mixed in dispersion into two solution phases in a liquid-liquid extraction separation cell (1). The arrangement includes a first guide wall (4), which is arranged at a distance from that end wall (15) of the cell (1) that is located on the side of the feed end (2), in order to extend along the whole width of the cell with respect to the vertical direction at an inclined angle (?). The first guide wall includes a bottom edge (5), which is located at a distance (H1 . . . H2) from the cell bottom, so that in between the bottom edge (5) and the cell bottom (3), there is left a clearance gap (6) widening from the center towards the cell sides. The second guide wall (7) is essentially parallel with the first guide wall (4) and placed at a distance (L1) therefrom, so that in between the first guide wall (4) and the second guide wall (7), there is formed an uptake shaft (8) extending diagonally upwards at an inclined angle (?).

Abstract: The invention relates to a method and arrangement for separating two solutions mixed in dispersion into two solution phases in a liquid-liquid extraction separation cell (1). The shut-off element (3, 4, 5) comprises a front panel (8) that extends along the whole width of the cell. The front panel (8) includes a bottom edge (9), which is arranged at a distance (H1, H2, H3) from the cell bottom (7), so that the front panel (8) allows an unobstructed flow of the heavier solution phase directly forwards underneath the bottom edge (9). In the vertical direction, the front panel extends to such a height that it forces the lighter solution phase placed on the heavier solution phase to flow as a thin overflow layer over the top edge (12) of the front panel (8) and forces the dispersion to thicken in front of the front panel.

Abstract: The invention relates to a method for reversing the dispersion formed in the mixing section of liquid-liquid extraction and kept condensed in the separation section and the separated solutions form the rear end of the separation section to flow back towards the feed end of the separation section. The invention also refers to the extraction equipment for implementing the reversed flow.

Abstract: The mixer apparatus accordant with the invention includes a closed reactor, at least two mixers at different heights, which are on the same shaft, a gas feed pipe below the lower mixer and baffles. The blades of the mixers are mostly rectangular in shape and a minimum of six in number. The angle of inclination of the blades of the lower mixer is around 50-70° and that of the upper mixer around 25-35°. The number of baffles is at least six and their range around 20% of the reactor diameter. The invention is focused also the corresponding method.

Abstract: The invention relates to a method and equipment with which an organic solution extraction solution is purified from entrainment of aqueous solution and impurities during hydrometallurgical liquid-liquid extraction. The method treats an organic extraction solution, which is loaded with a valuable metal or valuable substance from the aqueous solution. The purpose is to carry out the physical separation of water droplets and the chemical removal of impurities from the organic extraction solution simultaneously.

Abstract: The invention relates to a method and apparatus with which the aqueous solution from liquid-liquid extraction in the hydrometallurgical recovery of metals is purified from droplets of organic extraction solution. The aqueous solution is treated in a settling tank, where it is made to flow through a flow channel area with a reduced cross-section that extends over the width of the tank at least at one point. The flow channels are located in the lower section of the droplet coalescer according to the invention, with the upper section of the device being mainly solid.

Abstract: The invention relates to a method and apparatus with which an organic solution that is slightly soluble in water is scrubbed of aqueous entrainment and impurities. In particular, the organic solution may be the organic extraction solution of liquid-liquid extraction used in connection with the hydrometallurgical recovery of metals. The purpose is to perform the physical separation of water droplets and the chemical removal of impurities from the organic solution simultaneously. This occurs by routing the solution to be purified in the settling tank through at least one flow plate cassette of reduced cross-section.