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 method whereby copper is recovered from a copper sulphide ore containing pyrite. According to the method the ore is ground and leached into a solution containing sulfuric acid in atmospheric conditions by means of trivalent copper. As the copper sulphide leaches out, the trivalent iron is reduced to divalent and is oxidized back to trivalent by means of oxygen during leaching. Leaching is carried out in a closed reactor, where the undissolved gas rising from the solution in the supper section of the reactor is circulated back into the suspension of solution, solids and gas. leaching is performed in the presence of both divalent and trivalent iron and preferably with the dissolved copper acting as a catalyst to promote leaching. The conditions are adjusted to be such that the pyrite of the ore essentially does not dissolve.

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 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 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 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 present invention relates to a method for the treatment of copper-bearing materials, such as copper concentrates, so that the impurities and gangue minerals in the materials, such as silicates, are in effect removed completely.

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, by means of which the valuable metals contained in a sulphidic, multicomponent concentrate are recovered using hydrometallurgical treatment. One constituent of the concentrate is copper sulphide, which is leached using an alkali chloride-copper (II) chloride solution. The sulphides of other valuable metals, such as zinc, nickel, cobalt and lead are leached before copper leaching and each is recovered as a separate product before copper recovery.

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 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 invention relates to a method for the recovery of metals, in particular copper, from a copper-bearing raw material, whereby the material is leached into a chloride-containing solution. The leaching of the raw material is performed oxidatively and at a sufficiently high redox potential that the copper in the copper chloride solution from leaching is mainly divalent. The chloride solution obtained, which contains copper and potentially other valuable metals, is fed to liquid-liquid extraction. In the extraction the copper is first transferred to the organic phase with extraction and then to a sulphate solution in stripping, which is fed to copper electrowinning.

Abstract: The invention relates to a method for the controlled separation of a dispersion of two liquids formed in the mixing stage of liquid-liquid extraction into their own phases in the separation section of the extraction. In particular the method and equipment relate to the extraction process used in the recovery of metals. In accordance with the method the dispersion band remaining between the separated phases is dammed up using at least one revert member for said purpose located in the separation section. The equipment according to the invention comprises at least one revert member, which is in turn made up of at least two separate parts.

Abstract: The invention relates to a method whereby copper is recovered from a copper sulphide ore containing pyrite. According to the method the ore is ground and leached into a solution containing sulfuric acid in atmospheric conditions by means of trivalent copper. As the copper sulphide leaches out, the trivalent iron is reduced to divalent and is oxidized back to trivalent by means of oxygen during leaching. Leaching is carried out in a closed reactor, where the undissolved gas rising from the solution in the supper section of the reactor is circulated back into the suspension of solution, solids and gas. leaching is performed in the presence of both divalent and trivalent iron and preferably with the dissolved copper acting as a catalyst to promote leaching. The conditions are adjusted to be such that the pyrite of the ore essentially does not dissolve.

Abstract: The invention relates to a method for guiding a dispersion of two liquids formed in the mixing stage of liquid-liquid extraction along the longitudinal axis of the separation section in the feed end of an extraction separation section. In particular the method and equipment relate to the extraction process used in the recovery of metals. In accordance with the method the dispersion to be fed into the separation section is guided so that it spreads evenly over the cross-section of the separation section using a directional member placed so as to obtain a vertical flow. The equipment in accordance with the invention consists of a directional member, which is in turn made up of at least two separate parts.

Abstract: The invention relates to a method, by means of which the valuable metals contained in a sulphidic, multicomponent concentrate are recovered using hydrometallurgical treatment. One constituent of the concentrate is copper sulphide, which is leached using an alkali chloride-copper (II) chloride solution. The sulphides of other valuable metals, such as zinc, nickel, cobalt and lead are leached before copper leaching and each is recovered as a separate product before copper recovery.

Abstract: The present invention relates to a method for the treatment of copper-bearing materials, such as copper concentrates, so that the impurities and gangue minerals in the materials, such as silicates, are in effect removed completely.

Abstract: The invention relates to a method for the stabilization of the production capacity of an extraction plant extracting metals in a process, where the metal content of the feed solution varies. For the stabilization of capacity, the extraction cells and their piping are constructed and situated in such a way, that the extraction stages can be connected in different combinations, either in parallel or in a series. The method is especially suitable for the copper extraction process.

Abstract: The invention relates to a method for controlling and compressing a dispersion formed in the mixing stage of liquid-liquid extraction. The compression of the dispersion is achieved by reducing the cross-section of the separation section in the direction of flow and by equipping the separation section with a dispersion-damming member. The equipment according to the invention thus comprises a settler, which is essentially trapezoid in shape so that its cross-section is wider at the feed end of the settler and gets smaller towards the rear end of the settler, from whence the separated solutions are discharged from the settler, and the settler is equipped with at least one device to dam up the dispersion. In particular the method and equipment relate to the extraction process used in the recovery of metals.

Abstract: The invention relates to a method for the removal of metals from their aqueous solution with lime precipitation, in conditions where a precipitate of metal hydroxide and gypsum is formed, which settles well and is easy to filter. The metals are precipitated from their aqueous solutions at a high pH value and the slurry is recirculated several times in the precipitation space, whereby the gypsum is precipitated as separate crystals instead of a solid layer. The method is particularly suitable for neutralization of the aqueous solution from the pickling of refined steel. Using this method enables the removal of metals and fluoride from the water in question.