Diluent selection support device, diluent selection support method and program

Abstract

To support selection of a diluent in a solvent extraction method.SOLUTION: A diluent selection support device supports selection of a diluent in a solvent extraction method. The diluent selection support device includes a molecular information acquisition part for acquiring molecular information of an extractant molecule and a plurality of diluent molecules to be a candidate, a three-dimensional model generation part for generating a three-dimensional model including an organic phase and a water phase in the case of using each of the plurality of diluent molecules, a molecular dynamics calculation part for performing a molecular dynamics calculation in the three-dimensional model to calculate a pressure tensor in an interface between the organic phase and the water phase, and an interface tension calculation part for calculating interface tension in the interface on the basis of the pressure tensor calculated about each of the diluent molecules to be a candidate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a diluent selection support device, a diluent selection support method, and a program. [Background technology]

[0002] Solvent extraction (SX) is one method for selectively extracting metal ions contained in aqueous solutions. Solvent extraction uses two immiscible phases, and a combination of an organic phase (organic solvent) and an aqueous phase (aqueous solution) is widely used. Metal ions bind to the extractant added to the organic phase near the interface between the two phases and migrate into the organic phase. Therefore, the stability of the interface (phase separability) has a significant impact on the extraction equilibrium and extraction rate of metal ions.

[0003] Phase separation varies depending on the combination of organic solvent (also called diluent) and extractant, and is greatly influenced by the specific gravity, interfacial tension, and viscosity of the diluent. It is also related to the temperature of the system. In particular, phase separation is good when the interfacial tension is high.

[0004] Therefore, methods for selecting a diluent to be used in solvent extraction based on interfacial tension have been studied. For example, Patent Document 1 discloses an apparatus for measuring interfacial tension by the centrifugal liquid membrane method, which involves measuring an ultrathin film in a phase-separated state. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3751437 Summary of the Invention [Problem to be solved by the invention]

[0006] However, using the above-mentioned conventional techniques to experimentally measure interfacial tension and select a diluent has the problem of being time-consuming and costly when there are many candidate diluents.

[0007] The present invention has been made in view of the above circumstances, and aims to assist in the selection of a diluent in a solvent extraction method. [Means for solving the problem]

[0008] In order to achieve the above object, a diluent selection support device according to one aspect of the present invention comprises: A diluent selection support device for supporting the selection of a diluent in a solvent extraction method, comprising: a molecular information acquisition unit that acquires molecular information of the extractant molecule and a plurality of candidate diluent molecules; a three-dimensional model generating unit that generates a three-dimensional model including an organic phase and an aqueous phase when each of the plurality of diluent molecules is used; a molecular dynamics calculation unit that performs a molecular dynamics calculation on the three-dimensional model to calculate a pressure tensor at the interface between the organic phase and the aqueous phase; and an interfacial tension calculation unit that calculates the interfacial tension at the interface based on the pressure tensor calculated for each of the candidate diluent molecules. [Effects of the Invention]

[0009] It can assist in the selection of diluents for solvent extraction methods. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram illustrating an example of a functional configuration of a diluent selection support device. [Figure 2] 10 is a flowchart showing an example of the flow of a diluent selection support process. [Figure 3] FIG. 2 is a diagram illustrating an example of a hardware configuration of a diluent selection support device. [Figure 4] FIG. 1 is a diagram illustrating an example of a three-dimensional model. [Figure 5] FIG. 1 is a diagram showing an example of a molecular model of an extractant. [Figure 6] FIG. 10 is a diagram showing an example of an interfacial tension calculation result screen. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention (the present embodiment) will be described with reference to the drawings.

[0012] (Functional configuration of the diluent selection support device) FIG. 1 is a diagram illustrating an example of a functional configuration of a diluent selection support device.

[0013] The diluent selection support device 1 according to this embodiment is a device for supporting the selection of a diluent in a solvent extraction method. Specifically, the diluent selection support device 1 includes a molecular information acquisition unit 11, a 3D model generation unit 12, a molecular dynamics calculation unit 13, an interfacial tension calculation unit 14, a display unit 15, and a diluent selection unit 16.

[0014] The molecular information acquisition unit 11 acquires molecular information of the extractant molecule and multiple candidate diluent molecules. The molecular information is information that indicates the chemical structure of the molecule, and includes the number and types of atoms that make up the molecule, data indicating the relationships between the atoms, etc. The data indicating the relationships between the atoms includes the size of the atoms, the bonding atoms and the bond angles, etc.

[0015] The three-dimensional model generation unit 12 generates a three-dimensional model of a system having an organic phase and an aqueous phase. The three-dimensional model is data showing the arrangement of each molecule. The organic phase contains diluent molecules and extractant molecules, and the aqueous phase contains water molecules (and counter ions as necessary). Specifically, the three-dimensional model generation unit 12 generates, as a three-dimensional model, data showing the arrangement of each molecule in a system having an organic phase and an aqueous phase, based on the molecular information acquired by the molecular information acquisition unit 11 for each candidate diluent molecule. Here, the three-dimensional model generation unit 12 generates a three-dimensional model in which each molecule is dispersed and randomly arranged in space.

[0016] The molecular dynamics calculation unit 13 performs molecular dynamics calculations on the three-dimensional model generated for each candidate diluent molecule to calculate the pressure tensor.

[0017] The interfacial tension calculation unit 14 calculates the interfacial tension at the interface between the two phases based on the pressure tensor calculated for each candidate diluent molecule.

[0018] The display unit 15 displays information indicating the interfacial tension when each diluent is used for all candidate diluent molecules on a screen such as a display etc. The display unit 15 may also display information on another device, such as a terminal operated by a user.

[0019] The diluent selection unit 16 selects an optimum diluent based on the value of the interfacial tension. Furthermore, the display unit 15 may display information indicating the selected diluent.

[0020] (Operation of the diluent selection support device) Next, the operation of the diluent selection support device 1 will be described with reference to the drawings. Figure 2 is a flowchart showing an example of the flow of the diluent selection support process.

[0021] In response to a user's operation, the molecular information acquisition unit 11 acquires molecular information on the extractant molecule and a plurality of candidate diluent molecules (step S11).

[0022] Next, the 3D model generation unit 12 selects one of the candidate diluent molecules and generates a 3D model of a system having an organic phase and an aqueous phase based on the molecular information of the selected diluent molecule (step S12). Here, the 3D model generation unit 12 may perform structural optimization calculations such as molecular mechanics (MM) calculations, molecular dynamics (MD) calculations, and quantum mechanics (QM) calculations.

[0023] Next, the molecular dynamics calculation unit 13 calculates the pressure tensor at the interface by molecular dynamics calculation (step S13). The pressure tensor is expressed as a tensor (Pxx, Pyy, Pzz) using XYZ axes defined in advance in the space where the diluent molecules exist.

[0024] Specifically, the molecular dynamics calculation unit 13 performs a temperature rise calculation on the generated three-dimensional model, simulating a state in which the temperature is gradually increased to room temperature. Next, the molecular dynamics calculation unit 13 performs an NVT calculation, simulating a state in which the number of atoms, volume, and temperature are each maintained at specified values. Subsequently, the molecular dynamics calculation unit 13 performs an NPT calculation, simulating a state in which the number of atoms, pressure, and temperature are each maintained at specified values, and calculates the pressure tensor at the interface based on data from the last 0.1 ns of the NPT calculation.

[0025] Next, the interfacial tension calculation unit 14 calculates the interfacial tension based on the pressure tensor (step S14). Specifically, the interfacial tension calculation unit 14 calculates the interfacial tension σ by the following equation (1).

[0026] σ=(L / 2)×{Pzz-(1 / 2)×(Pxx+Pyy)}···(1) where (Pxx, Pyy, Pzz) is the pressure tensor and L is the cell size in the normal direction of the interface.

[0027] Next, the diluent selection support device 1 determines whether all diluents have been calculated (step S15). If the diluent selection support device 1 determines that there is a diluent that has not been calculated (step S15: NO), it returns to step S12, selects one of the diluents that has not yet been calculated, and executes the process.

[0028] When the diluent selection supporting device 1 determines that all diluents have been calculated (step S15: YES), the display unit 15 displays the calculation results of the interfacial tension (step S16).

[0029] Next, the diluent selection unit 16 selects a diluent, and the display unit 15 displays information indicating the selected diluent (step S17). Specifically, the diluent selection unit 16 stores in advance information that serves as a reference for selecting a diluent based on interfacial tension, and selects a diluent based on this information. For example, the diluent selection unit 16 may select a diluent whose interfacial tension is close to a reference value (e.g., 20 mN / m). Furthermore, the diluent selection unit 16 may select one diluent or multiple diluents, and may determine the order of the recommended diluents based on a reference standard.

[0030] The diluent selection support device 1 does not necessarily have to include the diluent selection unit 16, and does not necessarily have to perform the processes of steps S16 and S17. In this case, the user can select a diluent based on the displayed calculation result of the interfacial tension.

[0031] Next, a description will be given of the hardware configuration of the diluent selection support device 1. Fig. 3 is a diagram showing an example of the hardware configuration of the diluent selection support device.

[0032] The diluent selection support device 1 is configured by a computer and includes, for example, a CPU (Central Processing Unit) 101, a main memory device 102, an auxiliary memory device 103, an input device 104, a display device 105, a communication interface device 106, and a drive device 107. Each of these devices is connected via a bus.

[0033] The CPU 101 is a main control unit that controls the operation of the diluent selection assisting device 1, and realizes various functions described below by reading and executing programs stored in the main storage device 102.

[0034] The main memory device 102 reads and stores the program from the auxiliary memory device 103 when the diluent selection support device 1 is started up. The auxiliary memory device 103 stores the installed program as well as files, data, etc. required for various functions described later.

[0035] The input device 104 is a device for inputting various types of information and is realized by, for example, a keyboard, a pointing device, etc. The display device 105 is for displaying various types of information and is realized by, for example, a display, etc. The communication interface device 106 includes a LAN card, etc., and is used for connecting to other devices, etc.

[0036] The program according to this embodiment is at least a part of various programs that control the diluent selection assistance device 1. The program is provided, for example, by distributing a storage medium 108 or by downloading it from a network. The storage medium 108 on which the program is recorded can be of various types, including storage media that record information optically, electrically, or magnetically, such as a CD-ROM, a flexible disk, or a magneto-optical disk, and semiconductor memories that record information electrically, such as a ROM or a flash memory.

[0037] When storage medium 108 storing the program is set in drive device 107, the program is installed from storage medium 108 into auxiliary storage device 103 via drive device 107. A program downloaded from a network is installed into auxiliary storage device 103 via communication interface device 106.

[0038] (Example) An example of the diluent selection support device 1 according to this embodiment will be described. The extractant molecule is LIX63, and the candidate diluent molecules are (a) hexane (CH 14 ), (b) cyclohexane (CH 12 ), (c) benzene (C6H6), and the results are shown below.

[0039] 4 is a diagram showing an example of a three-dimensional model. The three-dimensional model generated by the molecular dynamics calculation unit 13 may be, for example, a model in which boxes 20 containing an organic phase 21 and an aqueous phase 22 are arranged in the X and Y directions. The length Lx of the box 20 in the X direction and the length Ly of the box 20 in the Y direction are each, for example, 50 angstroms, and the length Lz of the box 20 in the Z direction is, for example, 100 angstroms.

[0040] The three-dimensional model generation unit 12 generates two phases in a box 20: an organic phase in which approximately 25 molecules of extractant (LIX63) are arranged in a box containing approximately 600 molecules of candidate diluent molecules, and an aqueous phase containing approximately 4,300 molecules of water.

[0041] Fig. 5 is a diagram showing an example of a molecular model of an extractant. The molecular model shown in Fig. 5 illustrates molecular information (information indicating the arrangement of each atom and the bond relationship) acquired by the molecular information acquisition unit 11 as a molecular model of the extractant molecule LIX63.

[0042] 6 is a diagram showing an example of an interfacial tension calculation result screen. The interfacial tension calculation result screen 30 is an example of a screen displayed by the display unit 15 in step S16 of the diluent selection support process. The interfacial tension calculation result screen 30 displays the name of each diluent and the interfacial tension calculated for each diluent in association with each other.

[0043] Furthermore, the display unit 15 displays information indicating the diluent selected by the diluent selection unit 16 in step S17 of the diluent selection support process. For example, the diluent selection unit 16 selects cyclohexane, which has a value close to a reference value (e.g., 20 mN / m). The display unit 15 may display the selected cyclohexane on the interfacial tension calculation result screen 30 in a different character color from the others.

[0044] According to the diluent selection supporting device 1 of this embodiment, the interfacial tension is calculated by molecular dynamics calculation and used as an index of phase separability, thereby making it possible to support the efficient selection of a diluent.

[0045] The diluent selection support device 1 may further include a diluent selection unit 16 that selects a diluent based on the calculated interfacial tension, thereby reducing variations in diluent selection between users and enabling selection based on uniform criteria.

[0046] The diluent selector 16 may also select a diluent with an interfacial tension close to a preset reference value. If a diluent with too high an interfacial tension is selected, the diluent will be too stable and will not mix, resulting in an inactive interface. Conversely, if the interfacial tension is too low, the diluent will not be stable and will mix, preventing separation into two phases. Therefore, the diluent selector 16 can assist in the selection of an appropriate diluent based on a reference value that takes such a trade-off into account.

[0047] Furthermore, the 3D model generation unit 12 may generate a 3D model in which diluent molecules are randomly arranged by a structural optimization calculation. This eliminates the need to specify the arrangement of all molecules when creating a 3D model, making it possible to generate a 3D model with simple operations.

[0048] Furthermore, the molecular dynamics calculation unit 13 may calculate the pressure tensor by performing at least one of a temperature rise calculation, an NVT calculation, and an NPT calculation, which makes it possible to perform calculations for a large number of candidates, thereby reducing costs and effort.

[0049] The diluent selection support device 1 may further include a display unit 15 that displays the name of each candidate diluent molecule in association with information indicating the calculated interfacial tension, thereby providing the user with information to support the selection.

[0050] Although the present invention has been described above based on the present embodiment, the present invention is not limited to the requirements set forth in the above embodiment. These requirements can be changed without departing from the spirit of the present invention, and can be appropriately determined depending on the application form. [Industrial Applicability]

[0051] The present invention can be applied to the selection of a diluent when selectively extracting metal ions contained in an aqueous solution by solvent extraction. [Explanation of symbols]

[0052] 1. Diluent selection support device 11 Molecular Information Acquisition Department 12 3D model generation unit 13 Molecular Dynamics Calculation Department 14 Interfacial tension calculation section 15 Display section 16 Diluent selection section 20 boxes 21 Organic phase 22 Water phase 30 Interfacial tension calculation result screen 101 CPU 102 Main storage 103 Auxiliary storage device 104 Input Device 105 Display device 106 Communication interface device 107 Drive device 108 Storage medium

Claims

1. A diluent selection support device for supporting the selection of a diluent in a solvent extraction method, comprising: a molecular information acquisition unit that acquires molecular information of the extractant molecule and a plurality of candidate diluent molecules; a three-dimensional model generating unit that generates a three-dimensional model including an organic phase and an aqueous phase when each of the plurality of diluent molecules is used; a molecular dynamics calculation unit that performs a molecular dynamics calculation on the three-dimensional model to calculate a pressure tensor at the interface between the organic phase and the aqueous phase; an interfacial tension calculation unit that calculates an interfacial tension at the interface based on the pressure tensor calculated for each of the candidate diluent molecules, Diluent selection aid.

2. a diluent selection unit that selects a diluent based on the calculated interfacial tension; The diluent selection assistance device according to claim 1 .

3. the diluent selection unit selects the diluent having an interfacial tension close to a preset reference value. The diluent selection support device according to claim 2.

4. the three-dimensional model generation unit generates the three-dimensional model in which diluent molecules are randomly arranged by a structural optimization calculation. The diluent selection support device according to any one of claims 1 to 3.

5. the molecular dynamics calculation unit calculates the pressure tensor by performing at least one of a temperature rise calculation, an NVT calculation, and an NPT calculation; The diluent selection support device according to any one of claims 1 to 4.

6. a display unit that displays the name of the diluent for each of the candidate diluent molecules in association with information indicating the calculated interfacial tension; The diluent selection support device according to any one of claims 1 to 5.

7. 1. A computer-implemented method for assisting in the selection of a diluent in a solvent extraction process, comprising: obtaining molecular information for an extractant molecule and a plurality of candidate diluent molecules; generating a three-dimensional model including an organic phase and an aqueous phase when each of the plurality of diluent molecules is used; performing a molecular dynamics calculation on the three-dimensional model to calculate a pressure tensor at the interface between the organic phase and the aqueous phase; and calculating an interfacial tension at the interface based on the pressure tensor calculated for each candidate diluent molecule. A method for assisting in the selection of diluents.

8. A computer for assisting in the selection of a diluent in a solvent extraction method, obtaining molecular information for an extractant molecule and a plurality of candidate diluent molecules; generating a three-dimensional model including an organic phase and an aqueous phase when each of the plurality of diluent molecules is used; performing a molecular dynamics calculation on the three-dimensional model to calculate a pressure tensor at the interface between the organic phase and the aqueous phase; calculating the interfacial tension at the interface based on the pressure tensor calculated for each candidate diluent molecule; A program to execute.

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