JP5315537B2 - Method and apparatus for recovering nickel and phosphorous acid from nickel-containing aqueous solution - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method and apparatus for recovering nickel and phosphorous acid from a nickel-containing aqueous solution, and more particularly, a method and apparatus for efficiently extracting and recovering nickel and phosphorous acid from waste liquids of electroless nickel plating and electrolytic nickel plating. About.

  Electroless nickel plating solution used for surface treatment of electronic parts, precision machine parts, etc. is composed of nickel sulfate as a nickel supply source, sodium hypophosphite as a reducing agent, and complexing agents such as lactic acid and citric acid. . In the plating process, sodium hypophosphite is oxidized to sodium phosphite, and nickel is consumed along with it. Therefore, nickel sulfate, sodium hypophosphite, and sodium hydroxide are added as pH regulators as needed. . However, during repeated use of the plating solution, sulfate ions, sodium ions, phosphite ions, zinc and iron eluted from the surface of the object to be plated can accumulate in the plating solution and maintain the quality of the plating film. Since it becomes difficult, the plating solution used to some extent is disposed of as a waste solution. From the viewpoint of environmental protection and resource protection in recent years, development of a method for reusing used plating solutions is expected.

If the phosphite ions generated in the plating solution can be removed, the plating solution can be reused by adding nickel ions, so that the recovery and removal of phosphite ions is effective.
Therefore, as a method for reusing a used electroless nickel plating solution, for example, a method for preparing an electroless nickel replenisher from a waste solution using a nickel extractant such as 2-hydroxy-5-nonylacetophenone oxime is disclosed. (See Patent Document 1). However, when the above method is applied to an industrial scale continuous extraction device, a multistage extraction device, or the like, nickel cannot be efficiently recovered due to a low nickel extraction rate.

  In order to solve the above problems, a method for efficiently extracting and recovering nickel from a nickel-containing aqueous solution has been disclosed (see Patent Document 2). This method is characterized in that an organic solvent containing a β-hydroxyoxime-based extractant and an acidic organic phosphorus compound is brought into contact with a nickel-containing aqueous solution to extract nickel into the organic solvent phase. However, this method has a social problem that a large cost is required for the use or disposal of the organic solvent and an environmental load is imposed upon the disposal.

  As another prior art, a method is disclosed in which nickel ions are reacted with a chelate resin and removed by adsorption precipitation, and then nickel is eluted with an acid and recovered (Patent Document 3). However, this method uses a reaction flocculation water tank for the reaction, and a large water tank is required for collecting the precipitate, and the time required for the sedimentation separation is long, so that the process takes time and cost. there were.

  Moreover, the method of making alkaline by adding slaked lime containing calcium, etc., changing the dissolved nickel into insoluble nickel hydroxide, and filtering the precipitate is disclosed (Patent Document 4). However, this method has a problem that, in addition to the time and cost required for filtration of the precipitate, treatment chemicals such as slaked lime are required, and all of these are wastes that cannot be reused.

  Further, a method is disclosed in which a precipitation accelerator such as palladium is added to a plating waste solution to form a metallic nickel precipitate, which is filtered and solidified by a filter press (Patent Document 5). In this method, the nature of the precipitated precipitate is good, but there is a problem that a large equipment cost and space are required for the solidification step of the precipitate such as a filter press.

Furthermore, a method is disclosed in which nickel in the plating solution is deposited directly on the electrode surface by electrolysis using a copper electrode (Patent Document 6). Although this method is considered to be highly effective in recovering nickel, there is a problem in that a large amount of power is required for nickel deposition, resulting in large-scale equipment and high costs.
Japanese Patent Laid-Open No. 2001-192846 JP 2004-307983 A JP 11-226596 A Japanese Patent Application Laid-Open No. 10-066998 JP-A-10-180266 JP-A-11-124679

  Therefore, the present invention is a method capable of efficiently recovering nickel and phosphorous acid ions from a used plating solution, and reusing the recovered nickel and the recovered plating solution. An object of the present invention is to provide a novel method for recovering nickel and phosphorous acid from a nickel-containing aqueous solution that can recover nickel and phosphorous acid in a short time and at a low cost without requiring a small and large-scale apparatus. To do. Furthermore, it aims at providing the apparatus for it.

  In electroless nickel plating such as Kanigen plating, when nickel ions remaining in the nickel plating waste liquid are reused or when water purification is performed to remove nickel, nickel ions and phosphite ions are finally reused. A method of extraction as possible nickel hypophosphite is used.

  Here, since it is possible to generate a precipitate mainly composed of nickel phosphite by adjusting the pH of the nickel plating waste liquid, if it is possible to separate the precipitate mainly composed of nickel phosphite, the waste liquid treatment The process can be greatly shortened. However, since the precipitate containing nickel phosphite as a main component is in the form of a fine gel, adsorption to the filter and clogging occur even if it is separated by the filter. In addition, since this precipitate has a small specific gravity difference from the aqueous solution, the precipitate floats in the liquid even by a slight flow of the aqueous solution. For this reason, conventionally, separation as nickel phosphite has not been performed.

  Therefore, as a result of intensive studies on the method of separating the nickel phosphite, the inventor was adsorbed to a superconducting bulk magnet that generates a magnetic field of 3T (Tesla), although this gel-like precipitate is weak but magnetic. The inventors have found that they can be separated and have arrived at the present invention.

  That is, the method for recovering nickel from the nickel-containing aqueous solution according to the present invention includes a precipitation step of precipitating nickel phosphite by adjusting the hydrogen ion concentration of the nickel-containing aqueous solution containing phosphorous acid, and the sublimation precipitated in this precipitation step. And a separation step of separating the nickel phosphate by adsorption to a magnetic field.

  In the separation step, the strength of the magnetic field for adsorbing the nickel phosphite is 3T or more.

  Furthermore, a magnetic powder is added in the precipitation step or the separation step.

  The apparatus for recovering nickel from the nickel-containing aqueous solution of the present invention includes a reaction water tank for depositing nickel phosphite by adjusting the hydrogen ion concentration of the nickel-containing aqueous solution containing phosphorous acid, and nickel phosphite deposited in the reaction water tank. A precipitation water tank for adsorbing and separating the phosphide by a magnetic field, and a magnetic field generating means for generating a magnetic field for adsorbing nickel phosphite in the precipitation water tank.

  The magnetic field generating means is a superconducting bulk magnet.

  The magnetic field generating means is a superconducting solenoid magnet or an electromagnet.

  Further, the magnetic field generating means is a permanent magnet.

  Further, a magnetic mesh is arranged in the vicinity of the magnetic field generating means in the settling tank.

  Furthermore, a disk provided with a permanent magnet is disposed in the vicinity of the magnetic field generating means in the settling tank, and the disk is configured to be rotatable.

  According to the method for recovering nickel and phosphorous acid from the nickel-containing aqueous solution of the present invention, nickel and phosphorous acid can be obtained in a short time and at a low cost by adsorbing the nickel phosphite to the magnetic field without requiring a large-scale apparatus. Can be efficiently recovered.

  The nickel recovered as nickel phosphite can be synthesized by synthesizing nickel hypophosphite and added again to the nickel plating solution, and the remaining plating solution from which phosphite ions as impurities have been recovered and removed can be reused.

  By recovering and removing the phosphite ions generated in the plating solution as nickel phosphite, the plating solution can be reused by adding nickel ions, so that the entire life of the plating solution can be extended. .

  When draining the plating solution as a waste solution, nickel and phosphorous acid can be efficiently recovered and removed, which is effective for the purification of the waste solution.

  Moreover, nickel phosphite can be reliably adsorbed by setting the intensity of the magnetic field to 3 T or more.

  Furthermore, by adding magnetic powder, the sedimentation rate of nickel phosphite can be greatly increased and the separation efficiency can be improved.

  According to the apparatus for recovering nickel and phosphorous acid from the nickel-containing aqueous solution of the present invention, nickel and phosphorous acid can be obtained in a short time and at a low cost by adsorbing nickel phosphite to a magnetic field without requiring a large-scale apparatus. Can be efficiently recovered. At the same time, the plating solution from which phosphorous acid has been recovered and removed can be reused.

  In addition, since the magnetic field generating means is a superconducting bulk magnet, nickel phosphite can be efficiently adsorbed by the strong magnetic field and steep magnetic gradient of the bulk magnet, and the magnetic field generating means should be compact. Can do.

  Further, since the magnetic field generating means is a superconducting solenoid magnet, a large amount of nickel phosphite can be efficiently adsorbed by the strong magnetic field generated in a large space, and the magnetic field can be rapidly changed by being an electromagnet. Change of magnetic field, alternating magnetic field, and pulsed magnetic field, and the application range can be expanded and versatility can be improved.

  Further, since the magnetic field generating means is a permanent magnet, the apparatus can be simplified and the apparatus can be configured on a small scale at a low cost.

  Further, by providing a magnetic mesh in the vicinity of the magnetic field generating means, a steep magnetic field is generated by magnetizing the magnetic mesh, and the separation efficiency of nickel phosphite can be increased.

  Further, a disk having a permanent magnet is disposed in the vicinity of the magnetic field generating means, and by rotating the disk, the nickel phosphite adsorbed by the magnetic field generating means is attracted to the permanent magnet of the disk and separated. be able to.

  The method for recovering nickel and phosphorous acid from the nickel-containing aqueous solution of the present invention comprises a precipitation step of depositing nickel phosphite by adjusting the hydrogen ion concentration of the nickel-containing aqueous solution containing phosphorous acid, and the precipitation step A separation step of separating the nickel phosphite by adsorption to a magnetic field.

  The nickel-containing aqueous solution is not limited to the electroless nickel plating solution, and an electrolytic nickel plating solution and other nickel-containing aqueous solutions can be used. Moreover, the nickel containing aqueous solution containing the precipitation of organic substance and inorganic substance can also be used.

  In the precipitation step, nickel phosphite is precipitated by adjusting the hydrogen ion concentration of the nickel-containing aqueous solution. Since the nickel-containing aqueous solution is acidic when it is an electroless nickel plating solution, nickel phosphite can be precipitated by adding sodium hydroxide or the like to make it neutral. Further, in order to control the deposition rate of nickel phosphite, the temperature of the nickel-containing aqueous solution may be controlled.

  In the separation step, the nickel phosphite precipitated in the precipitation step is separated by being adsorbed by a magnetic field. By adsorbing nickel phosphite to a magnetic field, nickel and phosphorous acid can be efficiently recovered without requiring a large-scale apparatus and in a short time and at low cost.

  In the separation step, the strength of the magnetic field for adsorbing nickel phosphite is preferably 3T or more. By making the intensity of the magnetic field 3T or more, nickel phosphite can be reliably adsorbed. As a means for generating such a magnetic field, a superconducting bulk magnet, a superconducting solenoid magnet, an electromagnet, or a permanent magnet can be used.

  The separated nickel phosphite is dried and recovered as sludge. This sludge containing nickel phosphite as a main component can be added to the plating solution again by being transformed into nickel hypophosphite.

  According to the method for recovering nickel from the nickel-containing aqueous solution of the present invention, nickel can be efficiently recovered without requiring a large-scale apparatus and in a short time and at a low cost. Moreover, the chemical | medical agent to add is only sodium hydroxide and the cost concerning chemical | medical agent addition is very low.

  Furthermore, by adsorbing nickel phosphite by a strong magnetic field, it becomes possible to improve the sedimentation rate of nickel phosphite, shorten the residence time, and reduce the size of the sedimentation water tank, thereby greatly omitting the process. In addition, by refinement of critical particle size, reduction of suspended sediment (SS), and purification of supernatant liquid, fine precipitates and weak magnetic precipitates can be effectively agglomerated, improving separation and purification performance and improving throughput (throughput). Can be achieved.

  In addition, you may add a magnetic powder in the said precipitation process or the said isolation | separation process. As the magnetic powder, for example, iron oxide such as magnetite or hematite, or iron can be used. When the magnetic powder is added, the magnetic powder and nickel phosphite are adsorbed by the magnetic field and aggregate to increase the specific gravity, so that the sedimentation rate of nickel phosphite is greatly increased and the separation efficiency can be improved. Moreover, since nickel phosphite aggregates, suspended solids (SS) can be removed very efficiently.

  The nickel phosphite precipitate containing the magnetic powder can be recovered as a magnetic powder and reused by incineration in a furnace. Further, iron oxide and iron as added magnetic powder can be separated and recovered by centrifugation or re-dissolution of nickel phosphite.

  In the following examples, the recovery device for nickel and phosphorous acid from the nickel-containing aqueous solution of the present invention will be described with reference to the accompanying drawings.

  In FIG. 1 which shows the structure of the collection | recovery apparatus of the nickel from the nickel containing aqueous solution of a present Example, 1 is a nickel containing aqueous solution tank, The nickel containing aqueous solution containing phosphorous acid is transferred from this nickel containing aqueous solution tank 1 to the reaction water tank 2. It comes to be supplied.

  In the reaction water tank 2, a sodium hydroxide aqueous solution tank 3 for supplying a sodium hydroxide aqueous solution for adjusting the hydrogen ion concentration in the reaction water tank 2 to the reaction water tank 2 and a nickel-containing aqueous solution in the reaction water tank 2 are stirred. A stirring means 4 for heating and a heating means 5 for heating the aqueous solution in the reaction water tank 2 are provided. The nickel-containing aqueous solution in which nickel phosphite is precipitated by adjusting the hydrogen ion concentration in the reaction water tank 2 is supplied to the precipitation water tank 6.

  The precipitation water tank 6 has a magnetic field generating means 7 for generating a magnetic field for adsorbing the precipitate of nickel phosphite deposited on the bottom thereof, and a pipe for separating the nickel phosphite adsorbed by the magnetic field of the magnetic field generating means 7 8 is provided. In addition, a pipe 9 for separating the supernatant liquid is provided in the upper part of the precipitation water tank 6. In addition, 8a and 9a are valves provided in the pipes 8 and 9, respectively.

  The magnetic field generating means 7 is preferably one that can generate a magnetic field of 3 T or more in order to reliably adsorb nickel phosphite, and can be any of a superconducting bulk magnet, a superconducting solenoid magnet, an electromagnet, and a permanent magnet. Can be configured.

  Next, regarding the method of recovering nickel using the nickel recovery apparatus from the nickel-containing aqueous solution of this example, a nickel-phosphorous plating waste liquid called Kanigen plating or amorphous nickel plating is used as the nickel-containing aqueous solution containing phosphorous acid. The case where it is used will be described as an example.

  First, the plating waste liquid is supplied from the nickel-containing aqueous solution tank 1 to the reaction water tank 2. Then, the sodium hydroxide aqueous solution is added from the sodium hydroxide aqueous solution tank 3 to the reaction water tank 2 while being stirred by the stirring means 4 and, if necessary, heated by the heating means 5. And the gelled nickel phosphite precipitates by adjusting the hydrogen ion concentration, which is initially about pH 4.8, to a value close to pH 7 (neutral). The nickel-containing aqueous solution in which nickel phosphite is deposited is supplied to the precipitation water tank 6.

  In the precipitation water tank 6, the deposited nickel phosphite precipitate is attracted by the magnetic field generated by the magnetic field generation means 7 and quickly settles. And the gel-like precipitation A which aggregated to the bottom part of the precipitation water tank 6 is isolate | separated by extracting from the piping 8 via the valve | bulb 8a. Moreover, the supernatant liquid of the precipitation water tank 6 is extracted from the piping 9 through the valve 9a. In addition, in order to smoothly discharge the gel-like precipitate A without clogging the pipe 8, in addition to a method of discharging by water pressure due to gravity, a method of vacuuming and suctioning, a pumping installed in a part of the pipe A method may be used.

  Moreover, in the reaction water tank 2 or the precipitation water tank 6, magnetic powders, such as iron oxides, such as a magnetite and a hematite, and iron, may be added to the gel-like precipitation A of nickel phosphite, for example. By adding magnetic powder, the sedimentation rate of nickel phosphite is greatly increased and the separation efficiency is improved.

  As described above, the apparatus for recovering nickel from the nickel-containing aqueous solution according to the present embodiment includes the reaction water tank 2 for depositing nickel phosphite by adjusting the hydrogen ion concentration of the nickel-containing aqueous solution containing phosphorous acid, and this reaction. A precipitation water tank 6 for adsorbing and separating nickel phosphite deposited in the water tank 2 by a magnetic field and a magnetic field generating means 7 for generating a magnetic field for adsorbing the nickel phosphite in the precipitation water tank 6 are provided.

  Therefore, by adsorbing nickel phosphite to the magnetic field, nickel and phosphorous acid can be efficiently recovered without requiring a large-scale device and in a short time and at low cost. Further, the separation of nickel phosphite does not require a separation material such as a filter, and the nickel phosphite can be separated by continuous treatment. In addition, the magnetic field generating means is versatile, and a superconducting bulk magnet, a superconducting solenoid magnet, an electromagnet, or a permanent magnet can be selected depending on the scale and purpose of separation.

  Further, if a plurality of precipitation water tanks and magnetic field generating means are arranged in series in a multistage manner, higher separation efficiency can be easily obtained. Therefore, it can be used for the purification of nickel-containing wastewater.

  An apparatus for recovering nickel from the nickel-containing aqueous solution of this example will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to the said Example 1, and the detailed description is abbreviate | omitted.

  In this embodiment, the magnetic field generating means is composed of a superconducting bulk magnet. Reference numeral 10 denotes a superconducting bulk magnet as a magnetic field generating means, and a superconducting bulk material 11 as a magnetic pole is disposed close to the outside of the bottom surface of the settling tank 6. A cooling unit 12 is in contact with the superconducting bulk material 11, the cooling unit 12 is cooled by a refrigerator 13, and the superconducting bulk material 11 is further cooled by the cooling unit 12. Further, the bulk material 11 and the cooling unit 12 are accommodated in a vacuum vessel, and heat from the outside is cut off so that the bulk material 11 is maintained in a superconducting state. The bulk material 11 is excited in the superconducting state to generate a magnetic field. In addition, the superconducting bulk magnet 10 includes a vacuum pump, a compressor, and an excitation device, which are not shown.

  As described above, in the apparatus for recovering nickel from the nickel-containing aqueous solution of this example, the magnetic field generating means is the superconducting bulk magnet 10, and the nickel phosphite is efficiently obtained by the strong magnetic field of the bulk magnet and the steep magnetic gradient. Can be adsorbed and the magnetic field generating means can be made compact.

  An apparatus for recovering nickel and phosphorous acid from the nickel-containing aqueous solution of this example will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to the said Example 1, and the detailed description is abbreviate | omitted.

  In this embodiment, the magnetic field generating means is composed of a superconducting solenoid magnet. Reference numeral 14 denotes a superconducting solenoid magnet as a magnetic field generating means, and a magnetic pole is disposed close to the outside of the bottom surface of the settling tank 6. A pipe 8 is passed through the central bore 15 of the superconducting solenoid magnet 14.

  As described above, in the apparatus for recovering nickel from the nickel-containing aqueous solution of this example, the magnetic field generating means is the superconducting solenoid magnet 14, and the nickel phosphite is efficiently and massively produced by the strong magnetic field generated in a large space. Can be adsorbed.

  Moreover, it can be set as an electromagnet instead of a superconducting solenoid magnet by the same structure. Since the magnetic field generating means is an electromagnet, the change of the magnetic field can be a rapid magnetic field change, an alternating magnetic field, or a pulsed magnetic field, and the application range can be expanded and versatility can be improved.

  The apparatus for recovering nickel and phosphorous acid from the nickel-containing aqueous solution of this example will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to the said Example 1, and the detailed description is abbreviate | omitted.

  In this embodiment, the magnetic field generating means is composed of a permanent magnet. Reference numeral 16 denotes a permanent magnet as a magnetic field generating means, and a magnetic pole is arranged close to the outside of the bottom surface of the settling tank 6. A magnetic mesh 17 is disposed at the bottom inside the sedimentation tank 6. The magnetic mesh 17 is a net made of a relatively coarse magnetic material having an opening of about 0.1 mm to 10 mm. The opening of the pipe 8 is disposed in the vicinity of the magnetic mesh 17.

  As described above, in the recovery apparatus for nickel and phosphorous acid from the nickel-containing aqueous solution of this example, the magnetic field generating means is the permanent magnet 16, the apparatus can be simplified, and the apparatus can be reduced to a small scale at low cost. Can be configured.

  Further, a magnetic mesh 16 is arranged in the vicinity of the permanent magnet 16 serving as the magnetic field generating means in the settling water tank 6, and a steep magnetic field is generated by magnetizing the magnetic mesh 16, and the magnetic mesh 16 is made of nickel phosphite. Since the precipitate aggregates, the separation efficiency of nickel phosphite can be increased.

  The same effect can be obtained even when spherical or granular magnetic stainless steel or plated iron is disposed in the precipitation water tank 6 instead of the magnetic mesh 17. Further, the magnetic mesh 17 may be added to the configurations of the first to third embodiments to increase the separation efficiency of nickel phosphite.

  The apparatus for recovering nickel from the nickel-containing aqueous solution of this example will be described with reference to FIGS. 5 and 6 showing the configuration in the vicinity of the precipitation water tank. In addition, the same code | symbol is attached | subjected to the part similar to the said Example 1 and Example 2, and the detailed description is abbreviate | omitted.

  In this embodiment, a disk 22 is arranged upright in the precipitation water tank 6, and the lower part of the disk 22 is immersed in the nickel-containing aqueous solution in the precipitation water tank 6. A plurality of permanent magnets 22 are arranged at equal intervals on a circle centered on the central axis of the disc 21. The disc 21 is configured to be rotatable about its center, and is located on a circle on which the permanent magnet 21 is disposed in the vicinity of a portion of the disc 21 below the surface B of the nickel-containing aqueous solution. In addition, a superconducting bulk magnet 10 is disposed. Further, a scraper 23 for separating the precipitate adsorbed and collected by the disk 21 is provided in contact with the disk 21 above the liquid surface B. Reference numeral 24 denotes a storage tank for storing the precipitate separated from the disk 21 by the scraper 23, and reference numeral 25 denotes a pipe for discharging the supernatant liquid from which the precipitate has been separated.

  Next, the operation will be described. The strong magnetic field applied from the superconducting bulk magnet 11 collects the gel-like precipitate A in the settling tank 6. When the disk 21 is rotated, the precipitate A moves on the liquid surface B together with the permanent magnet 22 provided on the disk 21, is separated from the disk 21 by the scraper 23, and is stored in the storage tank 24. The As described above, the precipitate A aggregated in the vicinity of the superconducting bulk magnet 11 is moved together with the permanent magnet 22 in order to keep its position once collected, and is simply continuously led out of the precipitation water tank 6. The Further, since the precipitate A is separated from the disk 21 above the liquid level B, it is recovered as a good sludge with a low water content.

  As described above, the apparatus for recovering nickel from the nickel-containing aqueous solution according to the present embodiment has the disk 21 provided with the permanent magnet 22 in the vicinity of the superconducting bulk magnet 11 as the magnetic field generating means in the precipitation water tank 6. The disc 21 is configured to be rotatable, and the nickel phosphite adsorbed by the superconducting bulk magnet 11 can be adsorbed to the permanent magnet 22 of the disc 21 and separated.

  Note that instead of the disc 21, a belt-like shield made of cloth is installed, and this shield is moved on the superconducting bulk magnet 11, so that the precipitate A can be pulled up and separated.

  The pH of the nickel plating waste solution having a nickel concentration of 5400 ppm was adjusted, and nickel phosphite was precipitated and removed. The nickel concentration of the supernatant was 1500 ppm, which was reduced to the original 27.8%.

2 is a schematic diagram illustrating a configuration of a nickel recovery device from a nickel-containing aqueous solution of Example 1. FIG. 6 is a schematic diagram showing a configuration in the vicinity of a precipitation water tank of Example 2. FIG. 6 is a schematic diagram showing a configuration in the vicinity of a precipitation water tank of Example 3. FIG. FIG. 6 is a schematic diagram showing a configuration in the vicinity of a precipitation water tank of Example 4. It is a side view which shows the structure of the precipitation water tank vicinity of Example 5. FIG. FIG. 6 is a top view showing a configuration in the vicinity of a precipitation water tank of Example 5.

Explanation of symbols

2 Reaction water tank 6 Precipitation water tank 7 Magnetic field generation means
10 Superconducting bulk magnet (magnetic field generating means)
14 Superconducting solenoid magnet (magnetic field generating means)
16 Permanent magnet (magnetic field generating means)
17 Magnetic mesh
21 disc
22 Permanent magnet

Claims (9)

A precipitation step of precipitating nickel phosphite by adjusting the hydrogen ion concentration of a nickel-containing aqueous solution containing phosphorous acid, and a separation step of separating the nickel phosphite precipitated in this precipitation step by adsorbing to a magnetic field A method for recovering nickel and phosphorous acid from a nickel-containing aqueous solution. The method for recovering nickel and phosphorous acid from a nickel-containing aqueous solution according to claim 1, wherein the strength of the magnetic field for adsorbing nickel phosphite is 3 T or more in the separation step. 3. The method for recovering nickel and phosphorous acid from a nickel-containing aqueous solution according to claim 1 or 2, wherein magnetic powder is added in the precipitation step or the separation step. A reaction water tank for depositing nickel phosphite by adjusting the hydrogen ion concentration of the nickel-containing aqueous solution containing phosphorous acid, a precipitation water tank for adsorbing and separating the nickel phosphite deposited in the reaction water tank by a magnetic field, and this precipitation An apparatus for recovering nickel and phosphorous acid from a nickel-containing aqueous solution, comprising: a magnetic field generating means for generating a magnetic field for adsorbing nickel phosphite in a water tank. The apparatus for recovering nickel and phosphorous acid from a nickel-containing aqueous solution according to claim 4, wherein the magnetic field generating means is a superconducting bulk magnet. The apparatus for recovering nickel and phosphorous acid from an aqueous nickel-containing solution according to claim 4, wherein the magnetic field generating means is a superconducting solenoid magnet or an electromagnet. The apparatus for recovering nickel and phosphorous acid from a nickel-containing aqueous solution according to claim 4, wherein the magnetic field generating means is a permanent magnet. The apparatus for recovering nickel and phosphorous acid from a nickel-containing aqueous solution according to any one of claims 4 to 7, wherein a magnetic mesh is disposed in the vicinity of the magnetic field generating means in the precipitation water tank. 8. The disk according to claim 4, wherein a disk having a permanent magnet is disposed in the vicinity of the magnetic field generating means in the settling tank, and the disk is configured to be rotatable. An apparatus for recovering nickel and phosphorous acid from an aqueous nickel-containing solution.

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