JP2013231240A - Method and device for producing perchlorate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for producing perchlorate which monitors a generation amount of perchlorate ion by a simple method.SOLUTION: A method for producing perchlorate includes: a step of using an electrolysis tank in which an anode side provided with an anode and a cathode side provided with a cathode are partitioned by a cation exchange membrane, to electrolytically oxidize a sodium chlorate aqueous solution on the anode side; and a perchlorate ion amount measuring step of measuring a generation amount of perchlorate ion contained in the aqueous solution based on an amount of oxygen gas generated at the anode by the electrolytic oxidation and an amount of current in the electrolytic oxidation.

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for perchlorate.

  Ammonium perchlorate, one of the perchlorates, is used as an oxidizer for composite solid fuel rockets and is a useful material for the future of space development. Industrially, perchlorate is produced by electrolytically oxidizing a sodium chlorate aqueous solution synthesized by electrolytic oxidation of a sodium chloride aqueous solution to produce sodium perchlorate, and then performing a predetermined treatment. Here, as an electrolytic cell (electrolysis tank) for electrolytically oxidizing a sodium chlorate aqueous solution, an electrolysis described in, for example, Patent Documents 1 and 2 below, in which a diaphragm is provided between a non-diaphragm electrolysis cell having no diaphragm between the electrodes. There is a cell.

  The following two methods have been proposed as a method for producing ammonium perchlorate. One is a method in which sodium perchlorate is produced by electrolytic oxidation of a sodium chlorate aqueous solution using a diaphragmless electrolysis cell, and then ammonium sulfate is added to produce ammonium perchlorate by a metathesis reaction. The other is a method devised by the inventors of the present application, in which perchloric acid is generated by electrolytic oxidation of an aqueous sodium chlorate solution using an electrolytic cell provided with a diaphragm between electrodes, and then ammonia is added. Thus, ammonium perchlorate is produced by a neutralization reaction.

Japanese Patent Laid-Open No. 3-199387 JP 2007-197740 A

By the way, in said electrolysis process, judgment based on experience was made about the electrolysis time per time and the replacement | exchange time of the electrode consumed with electrolysis. Therefore, the optimum electrolysis time and electrode replacement time could not be objectively determined.
In addition, the electrolysis time per one time and the exchange time of an electrode depend on the production | generation efficiency of the perchlorate ion obtained by the electrolytic oxidation of a chlorate ion. Usually, liquid ion chromatography is used to measure the amount of perchlorate ions produced. However, the analysis apparatus has high analysis accuracy but takes time and labor for analysis, and is not suitable as a means for monitoring the amount of perchlorate ions produced.

  This invention is made | formed in view of the said problem, and it aims at providing the manufacturing method and manufacturing apparatus of the perchlorate which monitor the production amount of perchlorate ion by a simple method.

In order to solve the above problems, the present invention uses an electrolytic cell in which an anode side on which an anode is provided and a cathode side on which a cathode is provided are partitioned by a cation exchange membrane. Perchlorate ions for measuring the amount of perchlorate ions contained in the aqueous solution based on the amount of oxygen gas generated at the anode by the electrolytic oxidation and the amount of current in the electrolytic oxidation The manufacturing method of perchlorate which has quantity measurement process is adopted.
Thereby, in this invention, the production amount of perchlorate ion is estimated by estimating the production amount of perchlorate ion from the oxygen gas generation amount and the current amount.

Further, in the present invention, using an electrolytic cell in which an anode side on which an anode is provided and a cathode side on which a cathode is provided is partitioned by a cation exchange membrane, a step of electrolytically oxidizing a sodium chlorate aqueous solution on the anode side; Perchloric acid for measuring the amount of perchlorate ions contained in the aqueous solution based on the amount of oxygen gas generated at the anode by the electrolytic oxidation and the amount of hydrogen gas generated at the cathode by the electrolytic oxidation A method for producing perchlorate having an ion content measurement step is employed.
Thereby, in this invention, the production amount of perchlorate ion is estimated by estimating the production amount of perchlorate ion from the oxygen gas generation amount and the hydrogen gas generation amount.

  In the present invention, the anode side on which the anode is provided and the cathode side on which the cathode is provided are partitioned by a cation exchange membrane, and an electrolytic bath for electrolytically oxidizing a sodium chlorate aqueous solution on the anode side, An oxygen gas amount measuring device that measures the amount of oxygen gas generated at the anode, a current amount measuring device that measures the amount of current in the electrolytic oxidation, a measurement result of the oxygen gas amount measuring device, and a measurement of the current amount measuring device Based on the results, a perchlorate production apparatus having a perchlorate ion amount measuring device for measuring the amount of perchlorate ions contained in the aqueous solution is employed.

  In the present invention, the anode side on which the anode is provided and the cathode side on which the cathode is provided are partitioned by a cation exchange membrane, and an electrolytic bath for electrolytically oxidizing a sodium chlorate aqueous solution on the anode side, An oxygen gas amount measuring device that measures the amount of oxygen gas generated at the anode, a hydrogen gas amount measuring device that measures the amount of hydrogen gas generated at the cathode by the electrolytic oxidation, and a measurement result of the oxygen gas amount measuring device And a perchlorate ion amount measuring device for measuring the amount of perchlorate ions contained in the aqueous solution based on the measurement result of the hydrogen gas amount measuring device. Adopt equipment.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method and manufacturing apparatus of the perchlorate which monitor the production amount of perchlorate ion by a simple method are obtained.

It is a schematic block diagram of the ammonium perchlorate manufacturing apparatus in 1st Embodiment of this invention. It is a principal part block diagram of the ammonium perchlorate manufacturing apparatus in 1st Embodiment of this invention. It is a principal part enlarged view which shows the structure of the electrolytic cell in 1st Embodiment of this invention. It is a graph which shows the ultraviolet absorption spectrum of a hypochlorous acid solution, a chlorous acid solution, a chloric acid solution, and a perchloric acid solution. It is a graph which shows the change of the density | concentration of each component contained in the anolyte at the time of the electrolytic oxidation in 1st Embodiment of this invention. It is a principal part block diagram of the ammonium perchlorate manufacturing apparatus in 2nd Embodiment of this invention. It is a principal part block diagram of the ammonium perchlorate manufacturing apparatus in 3rd Embodiment of this invention. It is a principal part block diagram of the ammonium perchlorate manufacturing apparatus in 4th Embodiment of this invention. It is a graph which shows the relationship between the density | concentration of a sodium chlorate aqueous solution and a perchloric acid aqueous solution, and an ultraviolet light absorbency (transmittance).

Hereinafter, the manufacturing method and manufacturing apparatus of the perchlorate of embodiment of this invention are demonstrated with reference to drawings. In addition, below, the example at the time of applying this invention to the manufacturing method and manufacturing apparatus of ammonium perchlorate is demonstrated.
(First embodiment)
FIG. 1 is a schematic configuration diagram of an ammonium perchlorate production apparatus (perchlorate production apparatus) 1 in the first embodiment of the present invention. The symbols g, l, and s in the figure indicate a gas, liquid, and solid state, respectively. The ammonium perchlorate production apparatus 1 according to the first embodiment is roughly provided with an electrolytic cell 2 and a reaction / evaporation chamber 3.
FIG. 2 is a configuration diagram of a main part of the ammonium perchlorate production apparatus 1 according to the first embodiment of the present invention. As shown in the figure, the ammonium perchlorate production apparatus 1 includes a measuring device 8 that measures the amount of perchlorate ions produced.
FIG. 3 is an enlarged view of a main part showing the configuration of the electrolytic cell 2 in the first embodiment of the present invention.

The electrolytic cell 2 includes an anode 4, a cathode 5, a cation exchange membrane 6, and a platinum net 7. In the electrolytic cell 2, the anode side solution (anolyte) becomes strongly acidic and the cathode side solution (catholyte) becomes strongly alkaline due to electrolytic oxidation described later. It is desirable to use a material having excellent stability, such as Teflon (DuPont, registered trademark), vinyl chloride, or glass. In addition, it is desirable to use a pipe joint having excellent chemical resistance, such as Teflon (registered trademark).
The anode 4 of this embodiment uses a platinum-coated titanium expanded metal electrode in which titanium as a substrate is coated with a platinum catalyst layer 4a. As in the case of the anode 4, the cathode 5 of the present embodiment uses a platinum-coated titanium expanded metal obtained by coating titanium as a substrate with a platinum catalyst layer 5 a as an electrode.

The cation exchange membrane 6 is provided so as to partition the anode side 4A where the anode 4 is provided and the cathode side 5A where the cathode 5 is provided. The cation exchange membrane 6 constitutes a zero gap type electrolytic cell sandwiched between the anode 4 and the cathode 5 in the electrolytic cell 2 without a gap. This cation exchange membrane 6 is a membrane having the characteristics that it can pass cations but not anions. In this embodiment, Nafion 424 (Nafion, DuPont, registered trademark) is used as the cation exchange membrane 6. ) Is used. As the cation exchange membrane, Aciplex (Asahi Kasei Co., Ltd., registered trademark) or Flemion (Asahi Glass Co., Ltd., registered trademark) widely used in caustic soda production may be used.
Further, a platinum net 7 is sandwiched between the cation exchange membrane 6 and the anode 4 in order to promote the electrolytic synthesis reaction of chlorate ions on the anode side 4A. The mesh of the platinum mesh 7 is finer than the mesh of the expanded metal of the anode 4 and has a structure that increases the surface area that acts as a catalyst.

Returning to FIG. 2, the anode side 4A is provided with an anolyte tank 4B for storing the anolyte (hereinafter, the anode side 4A of the electrolytic cell 2 is referred to as the anode side electrolytic cell 2A). The liquid level of the anolyte in the anolyte tank 4B is higher than the liquid level in the anode side electrolytic cell 2A. The anolyte tank 4B and the anode side electrolytic cell 2A are connected by a pipe 27a and a pipe 27b. The pipe 27a connects the bottom of the anode electrolytic cell 2A and the bottom of the anolyte tank 4B, and the pipe 27b connects the top of the anode electrolytic tank 2A and the side of the anolyte tank 4B. Is.
A heater 4B1 for heating the anolyte is provided at the bottom of the anolyte tank 4B. Moreover, the thermocouple 4B2 which measures water temperature is provided in the side part of the anode side electrolytic cell 2A.

On the other hand, the cathode side 5A is provided with a catholyte tank 5B for storing catholyte (hereinafter, the cathode side 5A of the electrolytic cell 2 is referred to as a cathode side electrolytic cell 2B). The liquid level of the catholyte in the catholyte tank 5B is higher than the liquid level in the cathode side electrolytic cell 2B. The catholyte tank 5B and the cathode side electrolytic cell 2B are connected by a pipe 28a and a pipe 28b. The piping 28a connects the bottom of the cathode side electrolytic cell 2B and the bottom of the catholyte tank 5B, and the piping 28b connects the top of the cathode side electrolytic cell 2B and the side of the catholyte tank 5B. Is.
A heater 5B1 for heating the catholyte is provided at the bottom of the catholyte tank 5B. Moreover, the thermocouple 5B2 which measures water temperature is provided in the side part of the cathode side electrolytic cell 2B.

  An anolyte introduction pipe 21 is connected to the top of the anolyte tank 4B, and an aqueous sodium chlorate solution is introduced through the anolyte introduction pipe 21, and the anode side 4A (the anode side electrolytic cell 2A, the anolyte tank 4B). And filling the measurement tank 81 (including later). On the other hand, a catholyte introduction pipe 22 is connected to the top of the catholyte tank 5B, and pure water is introduced through the catholyte introduction pipe 22, and the cathode side 5A (cathode side electrolytic cell 2B, catholyte tank 5B). Meet). When voltage is applied to both electrodes of the anode 4 and the cathode 5 immersed in each solution inside the electrolytic cell 2, the following reaction proceeds.

On the anode side 4A, the sodium chlorate aqueous solution is electrolytically oxidized, and oxygen gas is generated as perchlorate ions and by-products as shown in the following reaction formulas (a) and (b). In addition, although it is a trace amount, as shown in the following reaction formula (c), ozone gas is also generated as a by-product.
ClO ₃ ⁻ + H ₂ O → ClO ₄ ⁻ + 2H ⁺ + 2e ⁻ ... (a)
2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ ... (b)
3H ₂ O → O ₃ + 6H ⁺ + 6e ⁻ ... (c)
Here, sodium ions contained in the liquid on the anode side 4A move from the anode side 4A to the cathode side 5A through the cation exchange membrane 6 due to the potential difference between the two electrodes. On the other hand, chlorate ions cannot pass through the cation exchange membrane 6 and become perchlorate ions by the reaction shown in the reaction formula (a) at the three interfaces constituted by the aqueous solution-platinum network 7-cation exchange membrane 6. In addition, this reaction can raise reaction efficiency by using the platinum net | network 7 with a mesh smaller than the mesh degree of an expanded metal.

The oxygen gas (bubbles) generated in the anode side electrolytic cell 2A is guided to the anolyte tank 4B through the pipe 27b. An oxygen gas pipe 23 is provided at the top of the anolyte tank 4B, and oxygen gas is sequentially exhausted to the outside through the oxygen gas pipe 23.
In addition, since the anolyte is sequentially introduced from the anolyte tank 4B from the bottom of the anode side electrolytic cell 2A through the pipe 27a due to the difference in liquid level (water pressure difference), the electrolytically oxidized anolyte is It is extruded from the electrolytic cell 2A to the anolyte tank 4B side through the pipe 27b. Accordingly, since the anolyte circulates between the anode side electrolytic cell 2A and the anolyte tank 4B regardless of the driving mechanism such as a pump, more anolyte is electrolytically oxidized in the anode side electrolytic cell 2A.

On the cathode side 5A, the reactions shown in the following reaction formulas (d) and (e) occur, and hydrogen gas and sodium hydroxide are generated.
2H ⁺ + 2e ⁻ → H ₂ (d)
2Na ⁺ + 2H ₂ O + 2e ⁻ → 2NaOH + H ₂ (e)
The hydrogen gas (bubbles) generated in the cathode side electrolytic cell 2B is guided to the catholyte tank 5B through the pipe 28b. A hydrogen gas pipe 24 is provided at the top of the catholyte tank 5B, and the hydrogen gas is sequentially exhausted to the outside through the hydrogen gas pipe 24. Similarly to the circulation of the anolyte at the anode side 4A, the circulation of the catholyte can be obtained at the cathode side 5A.

The measuring device 8 monitors a decrease amount of chlorate ions due to the electrolytic oxidation, and includes a measuring tank (another tank) 81, a light source 82, and a light receiver 83.
The measuring tank 81 is connected to the anolyte tank 4B by a pipe 84a and a pipe 84b. A quartz glass 81 </ b> A is provided at the top of the measurement tank 81. Similarly to the top, quartz glass 81B is provided at the bottom of the measuring tank 81.
The light source 82 irradiates the anolyte in the measuring tank 81 with ultraviolet rays through the quartz glass 81A. The light receiver 83 receives the ultraviolet rays irradiated by the light source 82 through the quartz glass 81B and measures the ultraviolet absorbance.

The measuring device 8 configured as described above transmits ultraviolet light through the anolyte, and monitors the amount of perchlorate ions generated by utilizing the difference in absorbance between chlorate ions and perchlorate ions (measurement step). This will be specifically described below.
FIG. 4 is a graph showing ultraviolet absorption spectra of a chloric acid solution and a perchloric acid solution (Source: Spring Co., Ltd. (http://www.e-h2o.net/orefernce1.html)).
In FIG. 4, the horizontal axis indicates the wavelength, and the vertical axis indicates the absorbance (0.0 to 1.0). An absorbance of 1.0 indicates that the ultraviolet rays are completely absorbed without passing through the solution. Further, when the absorbance is 0.0, it indicates that ultraviolet rays can pass through the solution and are not absorbed.
As shown in FIG. 4, it can be seen that the absorption shifts to the shorter wavelength side as the chloric acid solution, perchloric acid solution and oxidation become higher order. In particular, at a wavelength near 200 nm, the difference in absorbance between the chloric acid solution and the perchloric acid solution is noticeable. Therefore, the measuring device 8 in this embodiment uses ultraviolet rays having a wavelength near 200 nm.

FIG. 5 is a graph showing changes in the concentration of each component contained in the anolyte during electrolytic oxidation.
The concentration of chlorate ions in the anolyte decreases with time, while the concentration of perchlorate ions increases. Therefore, the absorbance of ultraviolet rays near the wavelength of 200 nm decreases with the electrolysis time. The measuring device 8 monitors the amount of decrease in chlorate ions with reference to the change in absorbance of the ultraviolet rays and the concentration of the introduced chlorate ions in the initial stage.

  Table 1 is an example of experimental results showing the difference in ultraviolet absorbance (transmittance) between an aqueous sodium chlorate solution and an aqueous perchloric acid solution when irradiated with ultraviolet rays having a wavelength of 193 nm.

In this experiment, a sample was put in a cell made of quartz glass, and a light source and a light receiver were placed opposite to each other with the cell interposed therebetween, and ultraviolet transmittance was measured. In this experiment, a light source for selecting and irradiating ultraviolet rays from a deuterium lamp with a 193 nm reflecting mirror was used. On the other hand, as a light receiver, a silicon PIN photodiode was used and connected to an oscilloscope to measure a change in voltage.
When the sodium chlorate aqueous solution (concentration 9.3 × 10 ⁻³ mol / L) was irradiated with ultraviolet rays having a wavelength of 193 nm, the transmittance was 31 (%). On the other hand, in the perchloric acid aqueous solution (concentration 23.3 mol / L), the transmittance was 46 (%). Thus, it can be seen that perchloric acid transmits ultraviolet light having a wavelength in the vicinity of 200 nm as compared with chloric acid.

Returning to FIG. 2, when it is determined by the measuring device 8 that a sufficient amount of perchlorate ions has been generated in the anolyte, the anolyte passes through the anolyte transport pipe 25 that has opened the valve 25A from the closed state. Via the anolyte tank 4B to the reaction / evaporation tank 3. On the other hand, the catholyte is transported to the outside from the catholyte tank 5B through the catholyte transport pipe 26 in which the valve 26A is opened from the closed state.
As shown in FIG. 1, the anolyte after electrolytic oxidation contains perchloric acid (HClO ₄ ), and also contains a small amount of chloric acid (HClO ₃ ) that has not been electrolytically oxidized.

The reaction / evaporation tank 3 synthesizes ammonium perchlorate by adding ammonia gas to the anolyte after electrolytic oxidation, and evaporates the synthesized anolyte under reduced pressure to crystallize ammonium perchlorate. And performing the analysis process. Here, an aqueous ammonia solution may be added instead of the ammonia gas.
An ammonia gas supply pipe 31 is connected to the reaction / evaporation tank 3 so that ammonia gas is bubbled into the anolyte after electrolytic oxidation. When ammonia gas is added to the anolyte after electrolytic oxidation, a neutralization reaction shown in the following reaction formula (f) occurs to synthesize ammonium perchlorate.
HClO ₄ + NH ₄ OH → NH ₄ ClO ₄ + H ₂ O ... (f)

  Next, in the reaction / evaporation tank 3, the synthesized anolyte is evaporated under reduced pressure to take out ammonium perchlorate as crystals. As shown in the reaction formula (f), since the by-product obtained together with ammonium perchlorate is water, high-purity ammonium perchlorate crystals can be obtained simply by evaporating the water.

Therefore, according to the first embodiment described above, the anode side 4A is used by using the electrolytic cell 2 in which the anode side 4A provided with the anode 4 and the cathode side 5A provided with the cathode 5 are partitioned by the cation exchange membrane 6. The electrolytic oxidation of the anolyte of the sodium chlorate aqueous solution and the measurement step of irradiating the electrolytically oxidized anolyte with ultraviolet light and measuring the amount of chlorate ions contained in the anolyte based on the ultraviolet absorbance. By adopting the production method of ammonium perchlorate, the amount of chlorate ion decrease associated with the generation of perchlorate ion is measured using the concentration dependence of chlorate ion with respect to ultraviolet absorbance, and the measurement result By estimating the production amount of perchlorate ions, the production amount of perchlorate ions can be monitored.
Therefore, in the first embodiment, the production amount of perchlorate ions can be monitored more easily than the conventional method. In addition, it is possible to increase the production efficiency of the aqueous perchloric acid solution required for the synthesis of ammonium perchlorate by objectively judging the electrolysis time per time and the replacement time of the electrode consumed with the electrolysis. .

  Moreover, in 1st Embodiment, the said measurement is employ | adopted by employ | adopting the structure that the anode 4 is provided and it is performed in the measurement tank 81 which is a tank different from the anode side electrolytic cell 2A which generate | occur | produces oxygen gas by the said electrolytic oxidation. Since ultraviolet rays are prevented from being scattered by bubbles, stable measurement results can be obtained.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, description of the part which has the same structure as the said embodiment is omitted.
FIG. 6 is a configuration diagram of a main part of the ammonium perchlorate production apparatus 1 according to the second embodiment of the present invention.
The ammonium perchlorate production apparatus 1 according to the second embodiment irradiates a sodium chlorate aqueous solution before electrolytic oxidation with ultraviolet rays, and measures the absorbance of the second measurement apparatus 9 and the measurement result of the measurement apparatus 8. 2 The third embodiment differs from the above embodiment in that it includes a third measurement device 10 that monitors the amount of decrease in chlorate ions during electrolytic oxidation based on the measurement result of the measurement device 9.

The second measuring device 9 has the same configuration as the measuring device 8 and includes a measuring tank 91, a light source 92, and a light receiver 93. The measuring tank 91 includes quartz glass 91A at the top and quartz glass 91B at the bottom. The measurement tank 91 is configured such that the anolyte before electrolytic oxidation is introduced through a pipe 21 a branched from the anolyte introduction pipe 21.
The third measuring device 10 is electrically connected to the light receiver 83 and the light receiver 93, and data of detection results of ultraviolet absorbance are input from both, and the chlorate ions after electrolytic oxidation are compared by comparing the data. A computer system for measuring the amount of Specifically, the third measuring apparatus 10 includes a memory that stores the data and a calculation program that calculates the amount of chlorate ions after electrolytic oxidation from the data, and a CPU that performs calculation processing based on the data and the calculation program. Have

The 2nd measuring device 9 irradiates the sodium chlorate aqueous solution before electrolytic oxidation with an ultraviolet-ray, and measures the light absorbency (2nd measurement process). The 3rd measuring device 10 memorizes the measurement result of the 2nd measuring device 9 as a standard value, measures the amount of decrease of chlorate ion by subtracting the standard value from the measurement result of measuring device 8, and from this measurement result The production amount of perchlorate ions is monitored by estimating the production amount of perchlorate ions (third measurement step).
Therefore, in the second embodiment, since the second measuring device 9 having the same configuration as the measuring device 8 is provided as described above and used as the reference light, the effect of improving the measurement accuracy of perchlorate ions can be achieved. is there.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. In addition, description of the part which has the same structure as the said embodiment is omitted.
FIG. 7 is a main part configuration diagram of the ammonium perchlorate production apparatus 1 according to the third embodiment of the present invention.
The ammonium perchlorate production apparatus 1 in the third embodiment is provided in an oxygen gas pipe 23, and includes a flow meter (oxygen gas amount measurement apparatus) 11 that measures the amount of oxygen gas generated at the anode 4 by electrolytic oxidation, and electrolysis. An ammeter (current amount measuring device) 12 that measures the amount of current used for oxidation, and a fourth measuring device (overcurrent) that estimates the amount of perchlorate ions generated based on the measurement results of the flow meter 11 and the ammeter 12. The chlorate ion amount measuring device) 13 is different from the above-described embodiment in that it is provided.

  The fourth measuring device 13 is electrically connected to the flow meter 11 and the ammeter 12, and data of detection results are input from both, and a computer system that calculates the amount of perchlorate ions generated based on the data. Have The 4th measuring device 13 estimates the production amount of perchlorate ion based on the arithmetic expression demonstrated below (4th measurement process (perchlorate ion amount measurement process)).

As described above, when the aqueous sodium chlorate solution is electrolyzed, the reaction of the reaction formula (a), the reaction formula (b), and the reaction formula (c) occurs on the anode side 4A.
ClO ₃ ⁻ + H ₂ O → ClO ₄ ⁻ + 2H ⁺ + 2e ⁻ ... (a)
2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ ... (b)
3H ₂ O → O ₃ + 6H ⁺ + 6e ⁻ ... (c)
In reality, a reaction in which platinum as an electrode material elutes into an aqueous solution as chloroplatinate ions (PtCl ₄ ²⁻ ) and an oxidation reaction of impurities (for example, chloride ions) contained in the raw material occur. However, the amount of products produced by these reactions is negligibly small compared to the amount of products produced by reaction formulas (a) and (b). Further, the reaction formula (c) is negligibly small as compared with the amount of the product generated by the reaction formula (a) and the reaction formula (b). Therefore, here, the formation reaction of chloroplatinate ions and the oxidation reaction of impurities are ignored, and when the sodium chlorate aqueous solution is electrolyzed, only the reactions of the reaction formulas (a) and (b) occur at the anode. Assume that

In estimating the amount of perchlorate ions generated from the amount of current and the amount of oxygen gas generated, the amount of oxygen gas generated when energized for t hours (unit: seconds) at current I (A) is expressed as V _O2 (unit: liter ( L)). Here, assuming a standard state (0 ° C., 1 atm), oxygen gas of V _O2 /22.4 (mol) was generated, and moved from the anode 4 to the cathode 5 with the generation of oxygen gas. The number of electrons e _O2 (mol) is four times V _O2 /22.4. On the other hand, the _total number of electrons e _total (mol) transferred from the anode 4 to the cathode 5 can be expressed by the following formula (1) using the Faraday constant F (= 9.6485 × 10 ⁴ C / mol). it can.

  Therefore, the number of electrons transferred from the anode 4 to the cathode 5 with the generation of perchlorate ions can be expressed by the following mathematical formula (2).

As a conclusion, the perchlorate ion generation amount W _ClO4- (g) should be estimated by the following formula (3) using the current amount It · t (C) and the oxygen gas generation amount V _O2 (L). Can do.

Here, κ ClO ₄₋ is the formula amount of ClO ₄ ⁻ and is 100.458 (g / mol).

Therefore, according to the third embodiment, the fourth measurement of measuring the amount of perchlorate ions generated based on the amount of oxygen gas generated on the anode side 4A by electrolytic oxidation and the amount of current used for the electrolytic oxidation. By adopting the configuration having the device 13, it is possible to estimate the amount of chlorate ions produced by using the oxygen gas generation amount and the current amount. In addition, according to the third embodiment, the production amount of chlorate ions can be estimated without providing an optical device that irradiates expensive ultraviolet rays, so that the cost can be reduced.
In addition, as shown in FIG. 7, by providing this configuration together with the measuring device 8 and comparing the measurement results of the two different measurement methods, the production amount of perchlorate ions can be accurately monitored with high reliability. Can do.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. In addition, description of the part which has the same structure as the said embodiment is omitted.
FIG. 8 is a configuration diagram of a main part of the ammonium perchlorate production apparatus 1 according to the fourth embodiment of the present invention.
The ammonium perchlorate production apparatus 1 according to the fourth embodiment is provided in an oxygen gas pipe 23, and includes a flow meter (oxygen gas amount measurement apparatus) 11 that measures the amount of oxygen gas generated at the anode 4 by electrolytic oxidation, Based on the measurement results of a flow meter (hydrogen gas amount measuring device) 14 provided in the gas pipe 24 and measuring the amount of hydrogen gas generated at the cathode 5 by electrolytic oxidation, and the flow meter 11 and the flow meter 14, The fifth embodiment is different from the above embodiment in that it includes a fifth measuring device (perchlorate ion amount measuring device) 15 for estimating the amount of acid ions generated.

  The fifth measuring device 15 is electrically connected to the flow meter 11 and the flow meter 14, receives detection result data from both, and calculates a perchlorate ion generation amount based on the data. Have The fifth measuring device 15 estimates a production amount of perchlorate ions based on an arithmetic expression described below (fifth measurement step (perchlorate ion amount measurement step)).

As described above, when the aqueous sodium chlorate solution is electrolyzed, the reaction of the reaction formula (a), the reaction formula (b), and the reaction formula (c) occurs on the anode side 4A.
ClO ₃ ⁻ + H ₂ O → ClO ₄ ⁻ + 2H ⁺ + 2e ⁻ ... (a)
2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ ... (b)
3H ₂ O → O ₃ + 6H ⁺ + 6e ⁻ ... (c)
In reality, a reaction in which platinum as an electrode material elutes into an aqueous solution as chloroplatinate ions (PtCl ₄ ²⁻ ) and an oxidation reaction of impurities (for example, chloride ions) contained in the raw material occur. However, the amount of products produced by these reactions is negligibly small compared to the amount of products produced by reaction formulas (a) and (b). Further, the reaction formula (c) is negligibly small as compared with the amount of the product generated by the reaction formula (a) and the reaction formula (b). Therefore, here, the formation reaction of chloroplatinate ions and the oxidation reaction of impurities are ignored, and when the sodium chlorate aqueous solution is electrolyzed, only the reactions of the reaction formulas (a) and (b) occur at the anode. Assume that

On the other hand, it is assumed that only the reactions shown in the following reaction formulas (d) and (e) occur on the cathode side 5A.
2H ⁺ + 2e ⁻ → H ₂ (d)
2Na ⁺ + 2H ₂ O + 2e ⁻ → 2NaOH + H ₂ (e)
Sodium ions move through the cation exchange membrane 6 which is a polymer solid electrolyte membrane from the anolyte side (anode side 4A) to the catholyte side (cathode side 5A) using the potential difference between the two electrodes as a driving force. As a result of the reduction reaction with water, sodium hydroxide and hydrogen gas are generated on the cathode side 5A.

In estimating the generation amount of perchlorate ions from the generation amount of oxygen gas and the generation amount of hydrogen gas, the generation amount of oxygen gas is V _O2 (unit: liter (L)), the generation amount of hydrogen gas is V _H2 (unit: Liter (L)). Here, assuming a standard state (0 ° C., 1 atm), oxygen gas of V _O2 /22.4 (mol) was generated, and moved from the anode 4 to the cathode 5 with the generation of oxygen gas. The number of electrons e _O2 (mol) is four times V _O2 /22.4. Similarly, for hydrogen gas, V _H2 /22.4 (mol) of hydrogen gas was generated, and the number of electrons e _H2 (mol) used in the reduction reaction was 2 of V _H2 /22.4. Doubled.
Therefore, the number of electrons transferred from the anode 4 to the cathode 5 with the generation of perchlorate ions can be expressed by the following mathematical formula (4).

As a conclusion, the perchlorate ion generation amount W _ClO4- (g) is estimated by the following formula (5) using the oxygen gas generation amount V _O2 (L) and the hydrogen gas generation amount V _H2 (L). be able to.

Here, κ ClO ₄₋ is the formula amount of ClO ₄ ⁻ and is 100.458 (g / mol).

Therefore, according to the fourth embodiment, based on the amount of oxygen gas generated on the anode side 4A by electrolytic oxidation and the amount of hydrogen gas generated on the cathode side 5A by electrolytic oxidation, the amount of perchlorate ions generated is reduced. By adopting the configuration of having the fifth measuring device 15 to measure, it is possible to estimate the production amount of chlorate ions by using the oxygen gas generation amount and the hydrogen gas generation amount. In addition, according to the fourth embodiment, the production amount of chlorate ions can be estimated without providing an optical device that irradiates expensive ultraviolet rays, so that the cost can be reduced.
In addition, as shown in FIG. 8, this configuration is provided together with the measuring device 8, and the measurement results of the two different measurement methods are compared to accurately monitor the amount of perchlorate ion generated with high reliability. Can do.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above-described embodiment, it has been described that both the anode 4 and the cathode 5 are made of platinum-coated titanium expanded metal, but the present invention is not limited to the above-described configuration.
As the anode 4, diamond-like carbon in which a crystalline component supporting platinum and an amorphous component are mixed may be used as an alternative to the platinum-coated titanium expanded metal.
The cathode 5 may use, for example, titanium expanded metal, SUS316L expanded metal, or nickel expanded metal as an alternative to platinum-coated titanium expanded metal.
Furthermore, from the viewpoint of corrosion resistance, not only platinum but also titanium expanded metal coated with gold, SUS316L expanded metal, or nickel expanded metal may be used.

  Moreover, the structure which combined 1st Embodiment, 2nd Embodiment, 3rd Embodiment, and 4th Embodiment may be sufficient as this invention.

In the present invention, the following means may be used in order to improve the monitoring accuracy of the amount of chlorate ion decrease based on the ultraviolet absorbance and the amount of perchlorate ion.
FIG. 9 is a graph showing the relationship between the concentration of an aqueous sodium chlorate solution and an aqueous perchloric acid solution and the ultraviolet absorbance (transmittance). In the figure, the vertical axis represents the transmittance, and the horizontal axis represents the concentration.
As shown in the figure, the change in the transmittance of chlorate ions tends to be smaller as the concentration is higher and larger as the concentration is lower. In other words, at the initial stage of electrolytic oxidation, since the concentration of sodium chlorate is high, the amount of chlorate ions must be measured from a minute change in transmittance, so it is difficult to monitor the decrease in chlorate ions. .
Therefore, this means employs a configuration in which the anolyte to be measured is diluted to adjust the concentration low, and measurement is performed in a range where the change in transmittance is large. Thereby, the decrease amount of chlorate ion, and hence the production amount of perchlorate ion can be monitored with high accuracy.

  Specifically, the anolyte on the anode side 4A is taken out, placed in a tank provided separately from the electrolytic tank 2, and diluted with pure water. Then, the measuring device having the same configuration as the measuring device 8 is irradiated with ultraviolet rays, and the amount of chlorate ions is measured based on the ultraviolet absorbance. Then, considering the diluted amount, a decrease amount of chlorate ions is derived from the measurement result. And the production amount of perchlorate ion is monitored from the decrease amount of this chlorate ion. The extracted and diluted anolyte may be returned to the electrolytic cell 2 again, but before that, for example, it is desirable to return it to the concentration of the anolyte in the electrolytic cell 2 by evaporating, for example. Thereby, the density | concentration change of the raw material by dilution water can be prevented.

  Further, the present invention is not limited to the above-described ammonium perchlorate production method and application to a production apparatus, and a method for producing alkali metal perchlorates such as lithium perchlorate and potassium perchlorate and The present invention can also be applied to a production apparatus, a production method and production apparatus for alkaline earth metal perchlorates such as calcium perchlorate, and a production method and production apparatus for silver perchlorate.

DESCRIPTION OF SYMBOLS 1 ... Ammonium perchlorate manufacturing apparatus (production apparatus of perchlorate), 2 ... Electrolyzer, 4 ... Anode, 4A ... Anode side, 5 ... Cathode, 5A ... Cathode side, 6 ... Cation exchange membrane, 8 ... Measuring device, 9 ... second measuring device, 10 ... third measuring device, 11 ... flow meter (oxygen gas amount measuring device), 12 ... ammeter (current amount measuring device), 13 ... fourth measuring device (perchloric acid) Ion amount measuring device), 14 ... flow meter (hydrogen gas amount measuring device), 15 ... fifth measuring device (perchlorate ion amount measuring device)

Claims (4)

Using an electrolytic cell in which an anode side on which an anode is provided and a cathode side on which a cathode is provided are partitioned by a cation exchange membrane, and electrolytically oxidizing a sodium chlorate aqueous solution on the anode side;
Having a perchlorate ion amount measurement step of measuring the amount of perchlorate ions contained in the aqueous solution based on the amount of oxygen gas generated at the anode by the electrolytic oxidation and the amount of current in the electrolytic oxidation. The manufacturing method of the perchlorate characterized. Using an electrolytic cell in which an anode side on which an anode is provided and a cathode side on which a cathode is provided are partitioned by a cation exchange membrane, and electrolytically oxidizing a sodium chlorate aqueous solution on the anode side;
Perchloric acid for measuring the amount of perchlorate ions contained in the aqueous solution based on the amount of oxygen gas generated at the anode by the electrolytic oxidation and the amount of hydrogen gas generated at the cathode by the electrolytic oxidation The manufacturing method of the perchlorate characterized by having an ion content measurement process. An electrolytic cell in which an anode side on which an anode is provided and a cathode side on which a cathode is provided are partitioned by a cation exchange membrane and electrolytically oxidizes a sodium chlorate aqueous solution on the anode side;
An oxygen gas amount measuring device for measuring the amount of oxygen gas generated at the anode by the electrolytic oxidation;
A current amount measuring device for measuring a current amount in the electrolytic oxidation;
A perchlorate ion amount measuring device that measures the amount of perchlorate ions contained in the aqueous solution based on the measurement result of the oxygen gas amount measurement device and the measurement result of the current amount measurement device. Perchlorate production equipment. An electrolytic cell in which an anode side on which an anode is provided and a cathode side on which a cathode is provided are partitioned by a cation exchange membrane and electrolytically oxidizes a sodium chlorate aqueous solution on the anode side;
An oxygen gas amount measuring device for measuring the amount of oxygen gas generated at the anode by the electrolytic oxidation;
A hydrogen gas amount measuring device for measuring the amount of hydrogen gas generated at the cathode by the electrolytic oxidation;
A perchlorate ion amount measuring device for measuring the amount of perchlorate ions contained in the aqueous solution based on the measurement result of the oxygen gas amount measurement device and the measurement result of the hydrogen gas amount measurement device. Perchlorate production equipment.

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