JP2019055354A - Method for removing droplet of water phase contained in organic phase - Google Patents

Abstract

To provide a method for effectively and efficiently removing a droplet of a fine water phase contained in an organic phase after extraction treatment using an organic solvent.SOLUTION: A method for removing a droplet of a water phase contained in an organic phase obtained from an extraction stage of performing extraction treatment using an organic solvent, where the organic phase passes through a pipe filled with glass beads. The method can be suitably used as a method for removing a droplet of a water phase contained in an organic phase after cleaning in the cleaning stage, in a solvent extraction method including three treatments in an extraction stage, the cleaning stage of cleaning the organic phase obtained from the extraction stage and a back extraction stage of subjecting the organic phase after cleaning to a back extraction treatment. The pipe is preferably a pipe of supplying the organic phase to the back extraction stage from the cleaning stage.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for removing fine aqueous phase droplets contained in an organic phase obtained from an extraction stage that performs extraction using an organic solvent.

  In the hydrometallurgical process that recovers the target metal from sulfides, the raw material nickel matte and nickel-cobalt mixed sulfide (MS: mixed sulfide) are leached with chlorine, and the liquid purification process removes impurities from the obtained leachate. Then, nickel and cobalt are recovered in the electrolysis process.

Specifically, for example, as shown in FIG. 1, the leachate obtained from the leaching step S1 is after copper is removed in the cementation step S2, and impurities such as iron and arsenic are removed in the deironing step S3. It is sent to the cobalt solvent extraction step S4. In the cobalt solvent extraction step S4, nickel and cobalt are separated by solvent extraction to obtain a nickel chloride solution (NiCl ₂ ) and a cobalt chloride solution (CoCl ₂ ). After the impurities are further removed in the liquid purification step S5, the nickel chloride solution becomes high purity and is sent to the nickel electrolysis step S6. In the nickel electrolysis step S6, electric nickel is produced by electrowinning. On the other hand, the cobalt chloride solution obtained in the cobalt solvent extraction step S4 is highly purified after impurities are removed in the liquid purification step S7, and is sent to the cobalt electrolysis step S8. And in cobalt electrolysis process S8, electric cobalt is manufactured by electrowinning.

  Here, FIG. 2 is a diagram illustrating an example of a processing flow in the cobalt solvent extraction step S4. In FIG. 2, “broken line” indicates the flow of the organic phase, and “solid line” indicates the flow of the aqueous phase.

  The cobalt solvent extraction step S4 is supplied with a post-treatment solution from which impurities have been removed through the iron removal step S3 as an extraction start solution. The extraction start solution is first supplied to the extraction step (extraction stage) S41. In the extraction step S41, cobalt in the extraction start liquid is extracted into the organic phase. The aqueous phase after extraction is sent to a subsequent process as a nickel chloride solution. Next, the organic phase in the extraction stage is sent to a washing step (washing step) S42, and nickel chloride contained in a trace amount in the organic solvent is removed in the washing step S42. Next, the organic phase from which nickel chloride has been removed is sent to a back extraction step (back washing step) S43. In the back extraction step S43, cobalt extracted into an organic solvent with an acidic aqueous solution such as dilute hydrochloric acid is moved to the water phase side. Back extraction results in a cobalt chloride solution. The produced cobalt chloride solution is sent to the post-process, while the organic solvent is repeated in the extraction step S41 and reused.

  In the extraction process in the extraction step S41, impurities such as zinc, iron, and copper are extracted into the organic phase together with cobalt. The extracted cobalt is back extracted into the aqueous phase in the back extraction step S43, but the impurities remain in the organic solvent without being back extracted. However, when the impurity concentration in the organic solvent increases, there arises a problem that the amount of cobalt extracted in the extraction step S41 decreases or impurities are eluted in the nickel chloride solution or the cobalt chloride solution. Therefore, the organic solvent after the process in the back extraction step S43 is sent to the dezincing step S44, and impurities such as zinc, iron, and copper are removed.

  In the back extraction process in the back extraction step S43, for example, a mixer settler is used, and the supplied organic phase and acidic aqueous solution (aqueous phase) are agitated and brought into contact with the mixer, so that cobalt in the organic phase is converted into the aqueous phase. Allow to partition and then settle to separate the organic-water phase. Thereby, the cobalt chloride solution is obtained as an aqueous phase. Since the organic phase separated through the back extraction process contains Zn, Fe, Cu, Ni, etc. as described above, these impurity components are removed by adding a neutralizing agent in the dezincing step S44. . Thereafter, the organic solvent from which the impurities are removed is sent to the activation step S45, an acidic aqueous solution is added, and the process is repeated in the extraction step S41.

  In the cobalt solvent extraction step S4, as described above, the washing step S42 is provided between the extraction step S41 and the back extraction step S43, and is included in the organic phase supplied from the extraction step S41. An aqueous phase mainly composed of an aqueous nickel chloride solution is removed. The aqueous phase containing nickel in the organic phase is included in the form of entrainment (fine droplets).

  The reason why the organic phase extracted in the extraction step S41 includes an aqueous phase is that the oil / water separation in the treatment in the extraction step S41 is insufficient, but in the extraction step S41, oil / water separation is performed by specific gravity separation. Therefore, in order to achieve sufficient oil-water separation, it is necessary to lengthen the residence time in the settler portion in the specific gravity separation process. However, the installation space and processing time are economically limited, and there is a limit to improving the performance of oil / water separation. For this reason, a washing step S42 is provided after the extraction step S41, and the aqueous phase contained as an entrainment in the organic phase is removed from the organic phase. Specifically, in the washing step S42, for example, by using a coalescer or the like, the aqueous phase that cannot be removed in the extraction step S41 and is included as an entrainment is removed.

  Thus, by removing the aqueous phase contained in the organic phase in the washing step S42, most of the aqueous phase containing nickel in the organic phase can be removed, but it is contained in the organic phase. Depending on the state of the impurity component, the deterioration of the organic solvent, etc., the water droplets may become invisible and slightly remain in the washed organic phase. Specifically, even in normal operation, the organic phase after the cleaning step S42 contains about 1 mg / L of nickel, and may remain at a rate of about 6 mg / L due to fluctuations in operation conditions.

  When such an organic phase is processed in the back extraction step S43, cobalt supported on the organic phase is distributed to the aqueous phase by the back extraction process. At the same time, nickel derived from the remaining aqueous phase is also distributed in the aqueous phase (cobalt chloride solution).

  The cobalt chloride solution after the back extraction treatment is supplied to the cobalt electrolysis step S8 through the cleaning (impurity removal) step S7, but there is no step of removing nickel as impurities contained in the cobalt chloride solution. In the cobalt electrolysis step S8, nickel having similar electrolysis conditions is electrodeposited simultaneously with cobalt, so that nickel is mixed as an impurity in the electric cobalt, and as a result, it deviates from the product standard of electric cobalt. There's a problem.

  In order to deal with the problems as described above, as shown in FIG. 2, a method of returning the cobalt chloride solution after the back extraction process back to the cleaning step S42 and performing the cleaning process can be considered, but the processing efficiency may deteriorate. In addition, even if repeated cleaning is performed, fine droplets that are invisible cannot be sufficiently removed.

  As technology for removing fine droplets, technologies such as coalescers and demisters that capture fine droplets, grow and coarsen them, and separate them into a state where specific gravity separation is possible are widely known, and related devices are also commercially available. ing. However, there is no known technique for removing fine particles of an unknown level by visual inspection of the organic phase mixed in the aqueous phase, and no known technique can be applied to fine oil (organic phase) droplets in a cobalt chloride solution. It is not done.

  Further, for example, Patent Document 1 discloses a technique for removing an oil phase in an aqueous phase. However, since it is a so-called drain and is a relatively large apparatus using an oil-adsorbing material, the above-described technology is disclosed. It is difficult to apply to the problem. Patent Document 2 also discloses a technique for removing the oil phase in the aqueous phase, but this technique is applied when the viscosity of the oil phase is very high such as pitch or tar. Since this is a relatively large device that requires a flow path that defines the flow direction of the target oil / water mixture, it is also difficult to apply. Further, Patent Document 3 discloses a technique for removing mist (fine droplets of water vapor) in order to suitably maintain the water balance in the dechlorination facility, but the liquid phase is removed from the gas phase. Technology.

JP-A-5-50060 International Publication No. 2011/71113 JP 2017-48436 A

  The present invention has been proposed in view of such circumstances, and effectively and efficiently removes fine water phase droplets contained in an organic phase after extraction using an organic solvent. An object is to provide a method capable of

  This inventor repeated earnest examination in order to solve the subject mentioned above. As a result, by passing the organic phase obtained from the extraction stage that performs the extraction process using an organic solvent through a pipe filled with glass beads, fine water phase droplets contained in the organic phase Has been found to be effectively removed, and the present invention has been completed.

  (1) The first invention of the present invention is a method for removing droplets of an aqueous phase contained in an organic phase obtained from an extraction stage that performs an extraction treatment using an organic solvent, wherein the organic phase is In this method, liquid is passed through a pipe filled with glass beads.

  (2) According to a second aspect of the present invention, in the first aspect, the extraction stage, a washing stage for washing the organic phase obtained from the extraction stage, and a back extraction treatment for the washed organic phase In the solvent extraction method including three treatments in the back extraction stage, the organic phase after washing in the washing stage is passed through a pipe filled with the glass beads.

  (3) A third invention of the present invention is the method according to the second invention, wherein the pipe is a pipe for supplying an organic phase from the washing stage to the back extraction stage.

  (4) According to a fourth aspect of the present invention, in any one of the first to third aspects, the glass beads filled in the pipe have an average particle diameter of 0.105 mm to 0.125 mm. Is the method.

  (5) According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the glass beads are filled at a height 1.5 to 3 times the cross-sectional diameter of the pipe. Is the way.

  (6) A sixth invention of the present invention is the method according to any one of the first to fifth inventions, wherein the glass beads are made of soda glass.

  (7) According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the solvent extraction method comprises extracting a cobalt chloride-containing nickel chloride solution as an extraction starting solution, and extracting the cobalt with a solvent. This is a method for obtaining a cobalt chloride solution, in which droplets of an aqueous phase containing nickel contained in the organic phase containing cobalt are removed.

  (8) The eighth invention of the present invention is the reverse of the extraction stage for performing an extraction process using an organic solvent, the washing stage for washing the organic phase obtained from the extraction stage, and the washed organic phase. A back extraction stage for performing an extraction process, wherein the washing stage and the back extraction stage are connected by a pipe for supplying an organic phase after washing in the washing stage, This is a solvent extraction device in which glass beads are filled in the middle of a pipe.

  (9) The ninth aspect of the present invention is the solvent extraction device according to the eighth aspect, wherein the pipe is branched into two or more flow paths, and each of the branched pipes is filled with the glass beads. It is.

  ADVANTAGE OF THE INVENTION According to this invention, the droplet of the fine water phase contained in the organic phase after the extraction process using the organic solvent can be removed effectively and efficiently.

It is a figure which shows an example of the flow of a hydrometallurgical process. It is a figure which shows an example of the flow of a process in a cobalt solvent extraction process. FIG. 3 is a schematic photograph of piping filled with glass beads used in Test Example 1.

  Hereinafter, specific embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention.

  The present invention is a method for removing water phase droplets (impurity components) contained in an organic phase obtained from an extraction stage that performs an extraction process using an organic solvent. More specifically, for example, three processes of an extraction stage, a washing stage for washing the organic phase obtained from the extraction stage, and a back extraction stage for performing a back extraction process on the washed organic phase In the solvent extraction method including the step of removing the aqueous phase contained in the organic phase after washing in the washing stage.

  For example, in the production process of a cobalt chloride solution, a countercurrent multistage extraction device is used to extract cobalt from a nickel chloride solution containing cobalt by solvent extraction with an organic solvent composed of an extractant and a diluent. Manufactures cobalt solutions. In this production process, an organic phase containing cobalt extracted by an organic solvent is transferred to a washing stage and subjected to a washing treatment to remove nickel as a so-called impurity component contained in the organic phase. Thereafter, the washed organic phase is transferred to a back washing stage and brought into contact with a back extract such as an acidic solution to desorb cobalt into the aqueous phase to produce a cobalt chloride solution.

  In this manufacturing process, although the organic phase after the extraction treatment in the extraction stage is subjected to a washing treatment in the washing stage, the aqueous phase containing nickel contained in the organic phase is almost removed, Invisible fine water phase droplets (entrainment) may remain without being removed.

  In the present invention, the organic phase containing fine water phase droplets obtained by the extraction process in the extraction stage, which occurs in such a manufacturing process, is placed in a pipe filled with glass beads in the middle of the pipe. It is characterized by allowing liquid to pass through.

  According to such treatment, it is possible to effectively remove invisible fine water phase droplets contained in the organic phase. In addition, since it can be processed by a simple method of filling glass beads in the middle of a predetermined pipe, there are no special restrictions due to processing costs and equipment installation space, such as installing large equipment, and it is economically efficient. Can be processed.

  In addition, FIG. 3 is a photograph figure which shows a mode when glass beads are filled in the middle of piping. In the present invention, an organic phase containing fine water phase droplets is passed through a pipe filled with such glass beads.

  The present inventor presumes the reason why fine droplets in the aqueous phase can be effectively removed by passing the organic phase through the glass beads as follows. That is, when the organic phase mixed with fine droplets (water droplets) is brought into contact with the glass beads, the water droplets adhere to the glass or the flow velocity decreases. Then, with the continuous flow of the organic phase, another water droplet comes into contact with the water droplet that has adhered to the glass or the flow velocity has decreased, and the water droplet gradually becomes coarse so that the separation from the organic phase is improved. As a result, it is conceivable that the aqueous phase is removed from the organic phase.

  Here, the organic phase including fine aqueous phase droplets includes an extraction stage, a washing stage for washing the organic phase obtained from the extraction stage, and a reverse extraction process for performing reverse extraction on the washed organic phase. In the solvent extraction method including three treatments in the extraction stage, the organic phase after washing in the washing stage is preferable.

  As described above, in the solvent extraction method including the three treatments in the extraction stage, the washing stage, and the back extraction stage, in the washing stage, the washing liquid is applied to the organic phase obtained by the extraction treatment with the organic solvent in the extraction stage. To remove a relatively large aqueous phase contained in the organic phase. In this way, by passing the organic phase from which the large aqueous phase droplets have been removed in the washing stage through the glass beads, it becomes easier for the droplets attached to the glass beads to become coarser and more effective. In addition, fine water phase droplets can be removed.

  The pipe for filling the glass beads is not particularly limited, but it is preferably a process pipe before the components extracted from the aqueous phase droplets contained in the organic phase are back-extracted. Among these, it is preferable that the pipe connects the washing stage and the back extraction stage and supplies the organic phase after the washing in the washing stage to the back extraction stage. As described above, the pipe for supplying the organic phase from the washing stage to the back extraction stage is a pipe through which the organic phase after washing is sent to the back extraction stage, and is filled with glass beads in the middle of the pipe. By allowing the organic phase containing the aqueous phase droplets to flow, the organic phase can be effectively removed without inhibiting the growth of the droplets.

  The shape of the glass beads is not particularly limited as long as it has an action that can be removed by effectively adhering fine water phase droplets contained in the organic phase or reducing the flow velocity. Things can be used. The size is preferably adjusted as appropriate according to the flow rate of the organic phase through which the glass beads are filled, but the average particle size is 0.105 mm to 0.500 mm. The thickness is preferably 0.105 mm to 0.350 mm, and more preferably 0.105 mm to 0.125 mm.

  As the glass beads, commercially available glass beads having a predetermined size can be used. The average particle diameter can be determined by a laser diffraction / scattering particle size distribution measurement method.

  The glass beads are preferably soda (lime) glass. Since soda glass is an inexpensive material, it can be appropriately processed without increasing the equipment cost.

  The filling of the glass beads into the pipe is not particularly limited, but the filling is preferably performed so that the filling height is 1.5 to 3 times, more preferably 2 times the cross-sectional diameter of the pipe. In addition, the cross-sectional diameter of piping means the internal diameter of piping. By filling the glass beads so that the filling height is in such a range, fine droplets can be more effectively adhered to glass beads having an average particle diameter of, for example, 0.105 mm to 0.500 mm. .

  The number of pipes installed is not particularly limited, but a plurality of pipes are preferably provided in parallel, and a switching valve or the like is preferably set so that the pipe to be used can be appropriately adjusted. Moreover, you may make it use what branched only one part of piping into two or more flow paths, without using multiple piping. In addition, when using branch piping, each branched piping is filled with glass beads. Even when a branch pipe is used, it is preferable that a switching valve or the like is provided at a branch point of the pipe so that the liquid passage of the organic phase can be switched.

  In this way, by using a pipe that secures two or more flow paths, it is not necessary to stop the entire apparatus even during maintenance such as work for replacing glass beads, and continuously stable operation is possible. .

  The amount of liquid flow when the organic phase is passed through the glass beads is not particularly limited, but it is preferable to adjust appropriately according to the filling capacity of the glass beads filled in the pipe, the particle diameter of the filled glass beads, and the like. The liquid flow rate is preferably in the range of about BV50 to BV300, and more preferably in the range of about BV100 to BV200.

  The temperature at which the organic phase is passed through the glass beads is not particularly limited, but the temperature of the organic phase is preferably in the range of about 45 ° C to 55 ° C. By passing the organic phase in such a temperature range, it is possible to pass with appropriate fluidity. Moreover, it is not necessary to perform special heating and cooling operations, and the processing can be performed efficiently.

  Here, the method according to the present invention is not particularly limited, but is suitable as a treatment in a production process (solvent extraction method) in which a nickel chloride solution containing cobalt is used as an extraction starting solution, and cobalt is subjected to solvent extraction to obtain a cobalt chloride solution. Can be applied to. More specifically, in the solvent extraction method for obtaining cobalt chloride, the present invention is applied to a method of removing droplets of an aqueous phase containing nickel contained in an organic phase containing cobalt obtained from an extraction stage. Can do. In this case, the aqueous phase contained in the organic phase is a solution containing nickel.

  In the solvent extraction method for obtaining a cobalt chloride solution, an amine-based extractant such as TNOA (Tri-n-octylamine) is preferably used as the extractant contained in the organic solvent used in the extraction stage. In the method according to the present invention, that is, the method for removing fine aqueous phase droplets from the organic phase, the fine aqueous phase droplets contained in the organic phase containing the amine-based extractant are more effectively removed. Can do.

  When the aqueous phase is removed from the organic phase by the above-described method, when the removed aqueous phase occupies a certain volume, the organic phase is observed as a droplet having a visible size in the aqueous phase. Sometimes. In such a case, a drain discharge space or the like may be provided below the branched and branched pipe as in a known oil-water separator so that the organic phase does not flow out.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

  Using an organic solvent in which TNOA (Farmin T-08, manufactured by Kao Corporation) as an extractant and Swazol N1800 (manufactured by Maruzen Petrochemical Co., Ltd.) as a diluent are mixed at a ratio of 20:80, cobalt is contained. Cobalt was extracted from the nickel chloride solution. Then, it sent to the washing | cleaning stage which wash | cleans an organic phase from an extraction stage, and wash | cleaned using the cobalt chloride solution as a washing | cleaning liquid.

  In this example, a process of removing fine water phase droplets contained in the washed organic phase obtained from the washing stage was performed.

  The organic phase after washing contained water phase droplets containing nickel at a nickel concentration of 100 mg / L. In addition, the nickel density | concentration in the organic phase after washing | cleaning when a malfunction does not arise is 1 mg / L or less. Considering the influence of nickel content in the subsequent process, the nickel concentration in the organic phase needs to be 6 mg / L or less, and it is necessary to remove the aqueous phase containing nickel at a removal rate of about 94% or more. .

  Specifically, in the operation of removing droplets of the aqueous phase from the organic phase, glass beads are filled in the middle of a glass pipe (inner diameter 10 mm) for supplying the washed organic phase from the washing stage to the back extraction stage. An organic phase containing organic water phase droplets (washed organic phase) was passed through the pipe.

  When filling the glass beads, the glass pipe is heated to about 50 ° C. by circulating hot water with a roller pump, and then the glass beads are filled to a filling height of 20 mm, which is twice the sectional diameter (inner diameter) of the pipe. The pipe was filled. At the time of filling, the filling height was adjusted by holding the glass beads with a stick.

  When passing the organic phase, the organic phase is preheated to about 50 ° C., and the organic phase is increased to a height of 22 cm in the glass pipe (20 cm excluding glass beads that are filled in the pipe). Was loaded. Then, the filtration pump was operated, the cock provided in the lower part of the glass piping was opened, and the liquid passing treatment was started. After passing through the pipe, the organic phase was recovered.

  Here, in Test Example 1, the pipe was filled with glass beads (product number BZ-01) having an average particle diameter of 0.105 mm to 0.125 mm. In Test Example 2, the pipe was filled with glass beads (product number BZ-04) having an average particle diameter of 0.350 mm to 0.500 mm. In Test Example 3, the pipe was filled with glass beads (product number BZ-08) having an average particle diameter of 0.710 mm to 0.990 mm. In addition, as for all the glass beads, those manufactured by AS ONE Corporation were used.

  Table 1 below shows the measurement results of the removal rate of nickel (aqueous phase) from the organic phase in each test example. “BV” refers to the magnification of the amount of liquid to be processed (organic phase) with respect to the filling material. It means that the liquid was passed through.

  FIG. 3 is an overview photograph of the pipe filled with glass beads used in Test Example 1, (A) is a photograph showing the state before the organic phase is passed, and (B) is the organic phase. It is a photograph figure which shows the state after passing through.

  As shown in Table 1, although there is a difference depending on the flow rate of the organic phase, the water phase can be obtained by a simple treatment of passing an organic phase containing fine water phase droplets through a pipe filled with glass beads. It was found that the liquid droplets can be effectively removed.

  Among them, in particular, when glass beads having a bead diameter of 0.105 mm to 0.125 mm were used, a removal rate of 94% or more was exhibited at any flow rate.

Claims (9)

A method for removing droplets of an aqueous phase contained in an organic phase obtained from an extraction stage that performs extraction using an organic solvent,
A method in which the organic phase is passed through a pipe filled with glass beads. In the solvent extraction method comprising three processes of the extraction stage, a washing stage for washing the organic phase obtained from the extraction stage, and a back extraction stage for performing a reverse extraction treatment on the washed organic phase, The method according to claim 1, wherein the organic phase after washing in the washing stage is passed through a pipe filled with the glass beads. The method according to claim 2, wherein the pipe is a pipe that supplies an organic phase from the cleaning stage to the back extraction stage. The method according to any one of claims 1 to 3, wherein the glass beads filled in the pipe have an average particle diameter of 0.105 mm to 0.125 mm. The method according to claim 1, wherein the glass beads are filled at a height that is 1.5 to 3 times the cross-sectional diameter of the pipe. The method according to claim 1, wherein the glass beads are made of soda glass. The solvent extraction method is a method in which a nickel chloride solution containing cobalt is used as an extraction starting solution, and the cobalt is solvent extracted to obtain a cobalt chloride solution.
The method according to any one of claims 1 to 6, wherein droplets of an aqueous phase containing nickel contained in the organic phase containing cobalt are removed. A solvent comprising an extraction stage for performing an extraction process using an organic solvent, a washing stage for washing the organic phase obtained from the extraction stage, and a back extraction stage for performing a reverse extraction process on the washed organic phase An extraction device,
The solvent extraction apparatus, wherein the washing stage and the back extraction stage are connected by a pipe for supplying an organic phase after washing in the washing stage, and glass beads are filled in the pipe. The pipe is branched into two or more flow paths,
The solvent extraction apparatus according to claim 8, wherein each of the branched pipes is filled with the glass beads.