JP6749152B2 - Method for regenerating alcohol amine-containing electrolyte - Google Patents

Description

The present invention relates to a method for regenerating an alcoholamine-containing electrolytic solution.

In a method of recovering tungsten from a raw material containing a valuable material containing tungsten, the present inventor performs electrolysis on a raw material containing a valuable material containing tungsten using an electrolyte solution containing alcohol amine. It has been found that tungsten can be efficiently recovered as a tungstic acid alcohol amine solution (Patent Document 1).
The method of Patent Document 2 is known as a method of distilling and purifying alcohol amine (alkanol amine). Since it is a method of purifying alkanolamine having a relatively high purity, it cannot be directly applied to an electrolytic solution of alcoholamine containing tungsten, but it can be efficiently decomposed by distilling under reduced pressure to suppress decomposition. ..
Further, Patent Document 3 discloses a method in which an organic amine used for the purpose of absorbing an acidic gas is once heated to drive out the acidic gas, and then regenerated by a treatment with an ion exchange resin. However, it is expected that it will be difficult to directly apply it to a liquid in which tungstic acid is dissolved.

Japanese Patent No. 5329615 Japanese Patent Publication No. 2001-521018 Patent No. 5585025

When a raw material containing a valuable material containing tungsten is electrolyzed using an electrolytic solution containing alcohol amine, tungsten is dissolved in the form of tungstic acid and/or polytungstic acid. As a result, the alcohol amine is neutralized and the pH of the liquid decreases.
On the other hand, when electrolysis is performed from a raw material containing a valuable material containing tungsten using an electrolyte solution containing alcohol amine, the pH of the electrolyte solution needs to be 6 or higher at the start of electrolysis or during electrolysis. If this is not done, tungstic acid or polytungstic acid may precipitate. Therefore, it is necessary to monitor the pH when the post-electrolysis solution is used for a long time, and to add alcohol amine when the pH falls below a predetermined range.
When the electrolytic treatment of the raw material containing tungsten is completed or the concentration of tungsten in the electrolytic solution rises to reach a certain level or higher, the tungsten is extracted and the tungsten is recovered. Since the extracted electrolytic solution also contains alcohol amine, it is necessary to separate and collect tungstic acid and/or polytungstic acid and reuse them.
However, if it is difficult to recover alcohol amine or if a large amount of cost is required, it is conceivable that the tungsten recovery process will not work.

Therefore, the present invention, when recovering tungsten by performing electrolysis using an electrolytic solution containing alcohol amine from a raw material containing a valuable material containing tungsten, alcohol contained in the electrolytic solution after recovering tungsten An object is to provide a method for efficiently recovering an amine.

The present inventor, as a result of extensive studies to solve the above problems, a group consisting of an alkaline earth metal hydroxide and an alkaline earth metal oxide in an electrolytic solution partially or wholly extracted to recover tungsten. It was found that tungsten can be separated as an alkaline earth metal salt of tungstic acid and alcoholamine can be recovered as a filtrate by adding at least one selected from the following, stirring in a solid-liquid mixed state, and then filtering. That is, it was found that even in an electrolytic solution containing alcohol amine, the tungsten dissolved in the electrolytic solution can be separated as an alkaline earth metal tungstic acid salt, specifically calcium tungstate or strontium tungstate. Once it is formed into the salt form of alkaline earth metal tungstic acid such as calcium tungstate, which is one of the intermediates in the tungsten recovery process, tungsten can be treated efficiently by conventional methods known up to now. It becomes possible to collect it.

When the concentration of impurities in the electrolytic solution is low, the tungsten is mixed with at least one selected from the group consisting of alkaline earth metal hydroxides and alkaline earth metal oxides to stir the tungsten with the alkaline earth metal tungstic acid. The salt can be separated and recovered by a method such as filtration, and the remaining liquid can be reused as an electrolytic solution as it is.
Since the electrolytic solution containing alcohol amine remains in the residue containing the alkaline earth metal salt of tungstic acid after filtration, the residue is washed with water. The washing liquid is also collected as needed, and the portion with a high concentration is sent to the purification/concentration step.

When recovering tungstic acid and/or polytungstic acid from the extracted electrolyte by ion exchange treatment, etc., acid such as hydrochloric acid may be mixed in alcohol amine during the ion exchange treatment, resulting in a decrease in pH. There is something to do. Further, water is added by a washing treatment after adsorbing tungstic acid and/or polytungstic acid on the ion exchange resin, and the concentration of alcohol amine is lowered.
From the above, the electrolytic solution diluted through the steps such as the ion exchange method needs to be concentrated.

There is another problem when the raw material containing tungsten is electrolyzed. In addition to tungstic acid and/or polytungstic acid and alcohol amine, the electrolytic solution may contain impurities mixed from the raw materials and substances produced by decomposition of alcohol amine in the process of electrolysis. For these reasons, it is often necessary to remove impurities and concentrate alcohol amines in the electrolytic solution.

In one aspect of the present invention completed based on the above findings, a raw material containing a valuable material containing tungsten is electrolyzed using an electrolyte solution containing alcohol amine, and after the electrolysis is performed. Step 1A for extracting a part or all of the electrolytic solution of 1., and at least one selected from the group consisting of alkaline earth metal hydroxides and alkaline earth metal oxides in the electrolytic solution extracted in Step 1A is tungsten. Step 1C of adding 1 to 5 times by mole ratio with and stirring and mixing in a solid-liquid mixed state to adjust pH to 9 to 13, Step 1D of collecting the filtrate by filtering the electrolytic solution after the step 1C And a step 1E of reusing the filtrate obtained in the step 1D as an electrolytic solution and washing the residue generated in the step 1D to recover the washing solution. ..

In one embodiment, the method for regenerating an alcoholamine-containing electrolytic solution of the present invention further includes a step 1F of treating the filtrate obtained in the step 1D with activated carbon.

In another embodiment of the method for regenerating an alcoholamine-containing electrolyte of the present invention, the method further includes a step 1G of separating impurities and concentrating alcoholamine by subjecting the cleaning liquid recovered in the step 1E to a vacuum distillation treatment. ..

In yet another embodiment, the method for regenerating an alcoholamine-containing electrolytic solution of the present invention further includes a step 1H in which the cleaning liquid is treated with activated carbon before or after the step 1G.

In another aspect of the present invention, a raw material containing a valuable material containing tungsten is electrolyzed using an electrolytic solution containing alcohol amine, and tungsten is obtained from the electrolytic solution after the electrolysis. In the solution before recovering tungsten or the solution after recovering tungsten, one or more selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides and alkaline earth metal oxides is added to tungsten. Step 2A of adding at a molar ratio of 1 to 5 times, stirring and mixing , adjusting the pH to 9 to 13, Step 2B of collecting the filtrate by filtering the electrolytic solution after Step 2A, and Step 2B. This is a method for regenerating an alcoholamine-containing electrolytic solution, which includes a step 2C in which impurities are separated and alcoholamine is distilled and recovered by subjecting the solution obtained in (1) to vacuum distillation.

In still another embodiment of the method for regenerating an alcoholamine-containing electrolytic solution of the present invention, the method further includes a step 2D in which the filtrate is treated with activated carbon before or after the step 2C.

In still another embodiment of the method for regenerating an alcoholamine-containing electrolytic solution of the present invention, the heating temperature of the solution in the vacuum distillation treatment of the step 2C is 60 to 120°C when components having a boiling point of up to 120°C are excluded. When recovering alcohol amine, the temperature is 120°C to 200°C.

In still another aspect of the present invention, for a raw material containing a valuable material containing tungsten, electrolysis is performed using an electrolytic solution containing alcohol amine, and the electrolytic solution after the electrolysis is performed. Step 3A of extracting a part or all of the extract, the liquid obtained in the step 3A is treated by an ion exchange method to adsorb tungstic acid and/or polytungstic acid to an ion exchange resin, and an alcohol amine excluding tungsten is included. In the step 3C of recovering the liquid, and in the liquid obtained in the step 3C, one or more selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides and alkaline earth metal oxides is used as tungsten. Separation of impurities by the step 3E in which the pH is adjusted to 9 to 13 by adding and mixing at a molar ratio of 1 to 5 times and mixing and stirring, and the liquid obtained in the step 3E is subjected to vacuum distillation treatment. And Step 3F of carrying out distillation recovery of alcohol amine.

In yet another embodiment, the method for regenerating an alcoholamine-containing electrolytic solution of the present invention further includes a step 3B of adjusting the viscosity by adding water to the electrolytic solution extracted in the step 3A, if necessary. Is used as a solution to be treated by the ion exchange method in the step 3C.

In still another embodiment of the method for regenerating an alcoholamine-containing electrolyte of the present invention, the ion exchange resin having adsorbed tungstic acid and/or polytungstic acid obtained in the step 3C is washed with water to recover the washing liquid. The step 3D is further included, and the collected cleaning liquid is used as a liquid for performing the vacuum distillation treatment in the step 3E.

In still another embodiment of the method for regenerating an alcoholamine-containing electrolytic solution according to the present invention, the method further includes a step 3G in which the solution is treated with activated carbon in a step before or after the step 3F.

In still another embodiment of the method for regenerating an alcoholamine-containing electrolytic solution of the present invention, the heating temperature of the solution in the vacuum distillation treatment of the step 3F is 60 to 120°C when components having a boiling point of up to 120°C are excluded. When recovering alcohol amine, the temperature is 120°C to 200°C.

In yet another embodiment of the method for regenerating an alcoholamine-containing electrolyte of the present invention, the alkali metal hydroxide is sodium hydroxide or potassium hydroxide, and the alkaline earth metal hydroxide is calcium hydroxide. , The alkaline earth metal oxide is calcium oxide.

In still another embodiment of the method for regenerating an alcoholamine-containing electrolytic solution of the present invention, the alcoholamine is methanolamine, ethanolamine, propanolamine, butanolamine, pentanolamine, dimethanolamine, diethanolamine, trimethanolamine. , Methylmethanolamine, methylethanolamine, methylpropanolamine, methylbutanolamine, ethylmethanolamine, ethylethanolamine, ethylpropanolamine, dimethylmethanolamine, dimethylethanolamine, dimethylpropanolamine, methyldimethanolamine, methyldiethanolamine and diethyl It is one or more selected from the group consisting of methanolamine.

In still another embodiment of the method for regenerating an alcoholamine-containing electrolytic solution of the present invention, the alcoholamine is triethanolamine, dibutanolamine, dipentanolamine, dihexanolamine, tripropanolamine, tributanolamine, One or more selected from the group consisting of methyldipropanolamine, methyldibutanolamine, methyldihexanolamine, ethyldipropanolamine, ethyldibutanolamine and butyldiethanolamine.

In still another embodiment of the method for regenerating an alcoholamine-containing electrolytic solution of the present invention, the alcoholamine is heptanolamine, decanolamine, nonanolamine, decanolamine, methylhexanolamine, methyloctanolamine, ethyl. It is one or more selected from the group consisting of pentanolamine, hexyldiethanolamine, dimethylhexanolamine, lauryldiethanolamine, benzylethanolamine and phenylethanolamine.

According to the present invention, an alcoholamine-containing electrolytic solution is efficiently prepared from a post-electrolysis solution after recovering tungsten by performing electrolysis using an electrolyte solution containing alcoholamine from a raw material containing a valuable material containing tungsten. A method of playing can be provided.

3 is a flowchart showing a method for regenerating an alcoholamine-containing electrolyte solution according to one aspect of the present invention. 5 is a flowchart showing a method for regenerating an alcoholamine-containing electrolyte solution according to another aspect of the present invention. 5 is a flowchart showing a method for regenerating an alcoholamine-containing electrolyte solution according to still another aspect of the present invention. It is a schematic diagram of an example of the electrolytic cell which electrolyzes the raw material containing tungsten.

The present invention provides a method for recovering and regenerating alcohol amine from an electrolytic solution containing alcohol amine in which tungsten is dissolved.
When a raw material containing a valuable material containing tungsten is electrolyzed using an electrolytic solution containing alcohol amine, and after the processing of the raw material is finished, or when the tungsten contained in the electrolytic solution reaches a predetermined concentration or more, , Extract a part of it and recover tungsten. Since the electrolytic solution after recovering the tungsten contains alcohol amine, it is reused.

First, the post-electrolysis solution to be treated will be described. The post-electrolysis solution is a solution obtained by electrolyzing a raw material containing a valuable material containing tungsten with an electrolyte solution containing alcohol amine. Further, the electrolytic solution after recovering the tungsten component from the electrolytic solution by ion exchange treatment is also targeted.

Examples of the raw material containing a valuable material containing tungsten include minerals containing tungsten, scrap (carbide) and the like. Further, more specifically, a so-called tungsten recycled material obtained by crushing tungsten scrap can be used. The raw material containing a valuable material containing tungsten to be treated in the present invention is, for example, 0 to 15 mass% for Co, 0 to 5 mass% for Ni, 0 to 5 mass% for Fe, 0 to 5 mass% for Ti, and Ta for Ta. It contains 0 to 15 mass% and the purity of tungsten is 3 to 95 mass %. The raw material containing a valuable material containing tungsten to be treated in the present invention may contain a valuable material other than tungsten in an amount of 1 to 30 mass %, or may contain a valuable material other than tungsten in an amount of 1 to 10 mass %. Of course, valuable materials other than tungsten may be contained in an amount of 3 to 10 mass %.

A raw material containing a valuable material containing tungsten is electrolyzed using an electrolytic cell equipped with an anode, a cathode, and an electrolytic solution containing alcohol amine to obtain a tungstic acid alcohol amine solution. The electrolytic cell is not particularly limited, but may have the configuration shown in FIG. 4, for example. In FIG. 4, a titanium basket is used as the anode, and a raw material containing a valuable material containing tungsten is provided in the titanium basket. Titanium baskets are preferable because they are stable under electrolytic treatment conditions of high voltage, high current and high temperature.

The tungsten concentration in the tungstic acid alcohol amine solution is not particularly limited, but is preferably 10 to 140 g/L. If the concentration of tungsten in the tungstic acid alcohol amine solution is less than 10 g/L, the problem that the amount of the solvent such as water is too large may occur, and if it exceeds 140 g/L, crystals may precipitate. The problem may occur. In the present invention, the tungstate ion is a monotungstate ion such as WO ₄ ²⁻ or a polytungstate ion such as HW ₆ O ₂₁ ⁵⁻ , H ₂ W ₁₂ O ₄₀ ⁶⁻ and W ₁₂ O ₄₁ ^{10 −.} Show.

Alcohol amines are methanol amine, ethanol amine, propanol amine, butanol amine, pentanol amine, dimethanol amine, diethanol amine, trimethanol amine, methyl methanol amine, methyl ethanol amine, methyl propanol amine, methyl butanol amine, ethyl methanol amine, It may be one or more selected from the group consisting of ethylethanolamine, ethylpropanolamine, dimethylmethanolamine, dimethylethanolamine, dimethylpropanolamine, methyldimethanolamine, methyldiethanolamine and diethylmethanolamine.

Alcohol amines include triethanolamine, dibutanolamine, dipentanolamine, dihexanolamine, tripropanolamine, tributanolamine, methyldipropanolamine, methyldibutanolamine, methyldihexanolamine, ethyldipropanolamine. It may be one or more selected from the group consisting of ethyldibutanolamine and butyldiethanolamine.

Further, alcohol amines include heptanolamine, decanolamine, nonanolamine, decanolamine, methylhexanolamine, methyloctanolamine, ethylpentanolamine, hexyldiethanolamine, dimethylhexanolamine, lauryldiethanolamine, benzylethanolamine and phenyl. It may be one or more selected from the group consisting of ethanolamine.

In this case, it is also necessary to keep the electric conductivity of the electrolytic solution high and prevent the cell voltage from increasing more than necessary. Since the cell voltage is greatly affected by the tungsten concentration in the electrolytic solution, it must be considered to maintain the tungsten concentration above a certain level. When adding alcohol amine or adding alcohol amine by extracting the electrolytic solution, the addition amount of alcohol amine and the extracting amount of the electrolytic solution may be adjusted so that the battery voltage does not exceed the set voltage.

The concentration of alcohol amine in the electrolytic solution is preferably 1 to 80 mass %. When the concentration of the alcohol amine in the electrolytic solution is less than 1 mass %, the conductivity becomes too low and the electrolysis becomes unstable, which may make the complex formation difficult. If the concentration of alcohol amine in the electrolytic solution exceeds 80 mass %, the solubility in water may be exceeded depending on the type of the electrolytic solution, and the concentration becomes higher than necessary, which is disadvantageous in terms of cost. The concentration of alcohol amine in the electrolytic solution is more preferably 2 to 50 mass%, even more preferably 5 to 40 mass%, and even more preferably 5 to 20 mass%.

The temperature of the electrolytic solution during electrolysis is preferably adjusted to 20 to 80° C. to perform electrolysis. When the temperature of the electrolytic solution is 20 to 80° C., the alcohol amine is stabilized, and the volatilization of the alcohol amine is favorably suppressed. Therefore, in the electrolytic reaction, there are advantages that the electrolytic solution does not volatilize, is stable, and has a small amount of impurities. Further, the temperature of the electrolytic solution is more preferably set to a high temperature of 60° C. or higher from the viewpoint of the electrolysis rate. For example, with ammonia, the volatilization is severe at 50° C. or higher and the amount of replenishment is large, but since alcohol amines have a high boiling point and are hard to volatilize, they can be used without problems at 60° C. or higher.

The alcohol amine used in the electrolytic solution has high withstand voltage and current density, and for productivity, it is preferable that the set voltage and set current density in electrolysis are both high, but equipment restrictions and cathode side Considering damage, it is preferable to set the set voltage to 20 V or less and the set current density to 500 A/dm ² or less because it is practical.

The pH of the electrolytic solution is preferably 7 or more. When the pH is less than 6, the generated tungstate ion cannot be dissolved and may be precipitated in the form of WO ₃ or H ₂ WO _4, etc., and as a result, electrolytic dissolution may be hindered. The electrolytic solution is more preferably adjusted to be weakly alkaline, for example, having a pH of 10 or more.

After performing the electrolysis as described above, the tungsten is recovered, and the electrolyte solution excluding the tungsten is prepared by using at least one selected from the group consisting of alkaline earth metal hydroxides and alkaline earth metal oxides. The alcohol amine contained in the electrolyte is treated so that it can be reused. The method for regenerating the alcohol amine-containing electrolytic solution of the present invention, specifically, can be shown in FIGS. 1, 2 and 3. The details will be described below.

A method of regenerating an alcoholamine-containing electrolytic solution according to one aspect of the present invention is shown in the flowchart of FIG. The method for regenerating the alcoholamine-containing electrolytic solution is such that a raw material containing a valuable material containing tungsten is electrolyzed using an electrolytic solution containing alcoholamine, and the electrolytic solution after the electrolysis is performed. 1A for extracting a part or all of the above, and one or more kinds selected from the group consisting of alkaline earth metal hydroxides and alkaline earth metal oxides are added to the electrolytic solution extracted in the step 1A, and solid-liquid mixing is performed. Step 1C of stirring and mixing in a state, Step 1D of filtering the electrolytic solution after the step 1C to recover a filtrate, and reusing the filtrate obtained in the step 1D as an electrolytic solution, and the step 1D Step 1E of washing the residue generated in step 1 to collect the washing liquid is included.
When electrolysis is performed from a raw material containing a valuable material containing tungsten using an electrolytic solution containing alcohol amine, the electrolytic solution must have a pH of 6 or higher at the start of electrolysis or during electrolysis. According to the configuration, the pH value lowered from the alkaline region during electrolysis can be returned to a high pH at which tungsten does not precipitate again, and further components unnecessary for electrolysis can be separated and removed. Therefore, alcohol amine contained in the electrolytic solution after recovering tungsten can be efficiently recovered.

You may further include the process 1F which processes activated carbon with the filtrate obtained by the said process 1D.
A step 1G of separating impurities and concentrating alcohol amine by subjecting the cleaning liquid collected in the step 1E to a vacuum distillation treatment may be further included.
It may further include a step 1H in which the cleaning liquid is treated with activated carbon before or after the step 1G.
With such a configuration, the treatment liquid can be concentrated when the concentration of the treatment liquid becomes diluted due to addition of the liquid necessary for the treatment in step 1C. Further, in the present invention, one or more kinds selected from the group consisting of alkaline earth metal hydroxides and alkaline earth metal oxides are added in order to bring the pH range into a reusable range for tungsten electrolysis. However, at this time, tungsten can be separated and recovered as a salt of an alkaline earth metal tungstic acid by a method such as filtration, and the remaining solution can be reused as an electrolytic solution as it is.

When one or more kinds selected from the group consisting of alkaline earth metal hydroxides and alkaline earth metal oxides of step 1C are mixed with the electrolytic solution, the alkaline earth metal to be added has a molar ratio of 1 to tungsten. It is preferably 5 times, preferably 1.5 to 3 times. When this value is less than 1, not only is tungsten separated incompletely, but also alcoholamine regeneration is likely to be incomplete. On the other hand, if it exceeds 5, the consumption amount of the alkaline earth metal increases, and an extra treatment cost may be required. This also applies to step 2A described later.

Although it is Step 1H of the above-mentioned activated carbon treatment, a treatment of adding activated carbon to a liquid containing activated carbon and alcohol amine, stirring and filtering may be used. However, when treating a large amount, it is preferable to use a packed column packed with activated carbon. Since this treatment is relatively simple, there are few restrictions on the treatment conditions, and there are many cases where it is sufficient to simply pass the liquid, but the space velocity SV is preferably 10 to 100 hr ⁻¹ , and 10 to 60 hr. It is more preferably ^-1 . This is the same for the steps 2D and 3G described later.

A method for regenerating an alcoholamine-containing electrolytic solution according to another aspect of the present invention is shown in the flowchart of FIG. The method for regenerating the alcoholamine-containing electrolytic solution is such that a raw material containing a valuable material containing tungsten is electrolyzed using an electrolytic solution containing alcoholamine, and the electrolytic solution after the electrolysis is performed. Add at least one selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides and alkaline earth metal oxides to the solution before recovering tungsten from the solution or after recovering tungsten. And stirring and mixing in step 2A, step 2B in which the electrolytic solution is filtered after step 2A to collect a filtrate, and vacuum distillation treatment is performed on the solution obtained in step 2B to separate impurities. It includes Step 2C of carrying out distillation recovery of alcohol amine.
With such a configuration, it is possible to separate and remove halogen, nitric acid, sulfuric acid, etc. that are mixed from the raw material, water, and the surrounding environment regardless of whether they are intentional or not. Some halogens, nitric acid, sulfuric acid, etc. form an inorganic salt soluble in water with an alkali metal or alkaline earth metal, and the most effective method for separating these from alcoholamine is distillation recovery of alcoholamine.
The inorganic salt may be added in order to increase the electric conductivity of the electrolytic solution, but when this concentration exceeds the control range, it can be removed by this process treatment.
Also, by this treatment method, it is possible to separate and remove unnecessary components for electrolysis even from an electrolytic solution whose pH has been lowered due to being left for a long period of time, or from a liquid containing alcohol amine but whose liquid composition is unknown. You can
Further, the treatment liquid can be concentrated when the concentration of the treatment liquid becomes thin due to addition of the liquid necessary for the treatment of step 2A.
By the above-mentioned treatment, components unnecessary for electrolysis such as an inorganic salt contained in the electrolytic solution can be removed and alcohol amine can be efficiently recovered.

It may further include a step 2D in which the filtrate is treated with activated carbon before or after the step 2C.
The heating temperature of the liquid in the vacuum distillation treatment of the step 2C may be 60 to 120°C when components with boiling points up to 120°C are removed, and may be 120°C to 200°C when alcohol amine is recovered.

The pH of the electrolytic solution after the alkali metal hydroxide or alkaline earth metal hydroxide treatment is adjusted to 9 to 13, preferably 9 to 12. When calcium hydroxide or calcium oxide is added, the solubility of calcium hydroxide is low, so that the probability of exceeding 12 is low. However, when an alkali metal coexists, the concentration of the alkali metal may increase due to ion exchange of carbonate ions. Even in this case, it is preferable to adjust the pH so as not to exceed 13.
Under conditions where the pH exceeds 13, the amount of scale increases when the alcohol amine is purified by the distillation treatment, which may complicate the treatment. On the other hand, when 9 is cut off, a salt of alcohol amine is produced, and regeneration of alcohol amine may be incomplete.

Although it is the distillation recovery step 2C by vacuum distillation, when the nonvolatile content such as metal salts contained in the liquid obtained in the step 2B is small, the boiling point of ammonia, water, etc., which first distills, is 120°C or lower. It can be reused only by removing the components and concentrating the alcohol amine. The concentrated solution may be treated with activated carbon as needed to adjust the alcohol amine concentration and then returned to the electrolytic solution for reuse.
In this case, the heating temperature is 60°C to 120°C. When it is sufficient to remove water, ammonia, amine and the like, the heating temperature is set to 60°C to 100°C. The heating temperature is the temperature of the heat medium used for heating.

When the amount of metal salt or the like and impurities having a high boiling point is large, it is necessary to further purify the alcohol amine. The alcohol amine is distilled and recovered by the method described in Patent Document 2 or the like. The heating temperature in this case is 100° C. to 300° C., but the optimum temperature varies depending on the type of alcohol amine, so it is appropriately adjusted. Usually, heating is performed in a range of about 40° C. below the boiling point of the alcohol amine and more than about 20° C. above the boiling point.

When the treatment amount is small, a rotary evaporator and an oil bath are used, and the temperature of the oil bath is set to about 100 to 180° C. to recover alcohol amine. The vacuum pump is preferably a water pump. This is because the liquid to be treated contains components such as water and amine having a low boiling point, and these components are less likely to deteriorate and are inexpensive. Of course, an ordinary rotary pump may be used, but deterioration of oil and corrosion of the pump often cause problems because a liquid containing water is treated. Therefore, it is necessary to use a cold trap to trap water and the like.

A method for regenerating an alcoholamine-containing electrolyte solution according to still another aspect of the present invention is shown in the flowchart of FIG. The method for regenerating the alcoholamine-containing electrolytic solution is such that a raw material containing a valuable material containing tungsten is electrolyzed using an electrolytic solution containing alcoholamine, and the electrolytic solution after the electrolysis is performed. Step 3A of extracting a part or all of the above, the liquid obtained in the above Step 3A is treated by an ion exchange method to adsorb tungstic acid and/or polytungstic acid to an ion exchange resin to remove alcohol amine excluding tungsten. Step 3C for recovering the liquid containing the liquid, and at least one selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides and alkaline earth metal oxides is added to the liquid obtained in the step 3C. And mixing/stirring step 3E, and step 3F of separating the impurities and distilling and recovering the alcohol amine by subjecting the liquid obtained in step 3E to a vacuum distillation treatment.
With such a configuration, halogen, nitric acid, sulfuric acid and the like mixed in the ion exchange treatment step can be separated and removed. Some halogens, nitric acid, sulfuric acid, etc. form an inorganic salt soluble in water with an alkali metal or alkaline earth metal, and the most effective method for separating these from alcoholamine is distillation recovery of alcoholamine.
Furthermore, in the case where the concentration of the treatment liquid becomes diluted due to the addition of the necessary liquid or the like in the treatment of steps 3A to 3C, the treatment liquid can be concentrated.
By the above-mentioned treatment, components unnecessary for electrolysis such as an inorganic salt contained in the electrolytic solution can be removed and alcohol amine can be efficiently recovered.

As a liquid for further treating the electrolytic solution extracted in the step 3A by adding water as necessary to adjust the viscosity, the electrolytic solution after the viscosity is adjusted by the ion exchange method in the step 3C. You may use.
The method further includes a step 3D of washing the ion exchange resin having adsorbed tungstic acid and/or polytungstic acid obtained in the step 3C with water to recover the washing liquid, wherein the collected washing liquid is subjected to the vacuum distillation treatment in the step 3E. You may use as a liquid to perform.
The method may further include a step 3G in which the liquid is treated with activated carbon in a step before or after the step 3F.
The heating temperature of the liquid in the vacuum distillation treatment of the step 3F may be 60 to 120°C when components with boiling points up to 120°C are removed, and may be 120°C to 200°C when alcohol amine is recovered.
The alkali metal hydroxide may be sodium hydroxide or potassium hydroxide, the alkaline earth metal hydroxide may be calcium hydroxide, and the alkaline earth metal oxide may be calcium oxide.

The operation of adsorbing tungstate ion to the ion exchange resin in step 3C will be specifically described as follows.
First, an alcohol amine electrolytic solution in which tungsten is dissolved is passed through an anion exchange resin to adsorb tungstate ions to the anion exchange resin. The tungsten concentration in the tungstic acid alcohol amine solution is not particularly limited, but is preferably 10 to 140 g/L. When the concentration of tungsten in the tungstic acid alcohol amine solution is less than 10 g/L, the problem that the amount of the solvent such as water is too large may occur, and when it exceeds 140 g/L, the anion exchange resin is filled. It is necessary to lengthen the resin packed tower to be used, which may cause a problem in terms of equipment cost. Further, if the resin packed tower is long in this way, crystals such as tungstic acid may be precipitated.

As described above, when a tungstic acid alcohol amine solution is obtained by electrolyzing a tungsten-containing super hard material with an electrolyte solution containing alcohol amine, tungstic acid is generated as a polyacid, and thus a special treatment is required. Without this, the adsorption capacity to the resin is increased more than that of monomolecular tungstic acid. Therefore, it can be favorably adsorbed on the anion exchange resin and the tungstate ion can be favorably separated from the alcohol amine.

In the present invention, the tungstate ion is a monotungstate ion such as WO ₄ ²⁻ or a polytungstate ion such as HW ₆ O ₂₁ ⁵⁻ , H ₂ W ₁₂ O ₄₀ ⁶⁻ and W ₁₂ O ₄₁ ^{10 −.} Show. When the alcohol amine of tungstic acid is being electrolyzed in the alcohol amine solution, even if the concentration of alcohol amine is lower than the equivalent of monotungstic acid, it exists as a stable solution. Therefore, it can be seen that most of it is produced as polytungstic acid.

The anion exchange resin may be either type I or type II, but in order to adsorb tungstic acid efficiently, type I, which is a strong base, is preferably used. Further, since an alcohol amine solution is used, an ion exchange resin that can be stably used in an organic solvent is preferable. Specific examples thereof include Amberlite IRA900J and Amberlite IRA904 manufactured by Dow Chemical Company.

The resin-packed tower filled with the anion exchange resin may be a single one, or may be two or more continuously used. Further, such a resin packed tower may be, for example, a tube having an inner diameter of 2 to 500 cm packed with an anion exchange resin at a height (length) of 15 to 1000 cm. Liquid permeation speed of tungstate alcoholic amine solution is not particularly limited, but is preferably a space velocity SV is 0.5～10Hr ^-1, and more preferably 0.8~5hr ^-1.

Further, in the step of adsorbing tungstate ion to the anion exchange resin, the after-passing solution obtained by passing the tungstate alcohol amine solution through the anion exchange resin is returned to the anion exchange resin and passed again. You may make it liquid. In the post-liquid-passage solution obtained by passing the tungstic acid alcohol amine solution through the anion exchange resin, polytungstate ions that have not been adsorbed by the anion exchange resin may remain. Therefore, with the above-described structure, the liquid after passing the liquid can be passed through the anion exchange resin again to recover a larger amount of polytungstate ion.

The ion exchange resin having the tungsten adsorbed by the ion exchange treatment is washed with water. The electrolytic solution after recovering tungsten and the solution obtained by washing the ion exchange resin with water are one kind selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides and alkaline earth metal oxides. The above processing is performed.

At least one selected from the group consisting of the above-mentioned alkali metal hydroxides, alkaline earth metal hydroxides and alkaline earth metal oxides, but as described above, sodium hydroxide, potassium hydroxide, calcium hydroxide. Alternatively, it is preferable to use calcium oxide.
Alkali metal hydroxides such as lithium hydroxide and rubidium hydroxide, and barium hydroxide, strontium hydroxide, and alkaline earth metal hydroxides such as magnesium hydroxide can be used, but in terms of price and availability. It tends to be expensive. Therefore, it is preferable to use calcium hydroxide or calcium oxide.

The pH of the electrolytic solution after treatment with one or more selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides and alkaline earth metal oxides is 9 to 13, preferably 9 to Adjust to be 12. When calcium hydroxide or calcium oxide is added, the solubility of calcium hydroxide is low, so that the probability of exceeding 12 is low. However, when an alkali metal coexists, the concentration of the alkali metal may increase due to ion exchange of carbonate ions. Even in this case, it is preferable to adjust the pH so as not to exceed 13.
Under conditions where the pH exceeds 13, the amount of scale increases when the alcohol amine is purified by the distillation treatment, which may complicate the treatment. On the other hand, when 9 is cut off, a salt of alcohol amine is produced, and regeneration of alcohol amine may be incomplete.

When calcium hydroxide or calcium oxide is used, it is also possible to remove the carbonate generated by dissolving carbon dioxide in the air in the post-electrolysis solution. Therefore, it can be suitably used for regenerating the electrolytic solution used for a long time.

Examples of the present invention will be described below, but the examples are for illustrative purposes and are not intended to limit the invention.

(Example 1)
As the anode of the electrolytic cell, 10 kg of cemented carbide scrap of the grade shown in Table 1 was placed in a titanium basket.
A titanium plate was used as the cathode of the electrolytic cell.
200 g of monoethanolamine was used as the electrolytic solution to make 10 L with pure water. Next, a rectifier was connected, and electrolytic dissolution was carried out for 10 hours at a current density of 5 A/dm ² and a constant current of 100 A at a temperature of 70°C. The amount of dissolved tungsten was 600 g, and the pH of the electrolytic solution was 7.1.

1 L of this electrolytic solution was sampled, calcium oxide powder was added little by little while stirring at a temperature of 50° C., and finally 50 g of calcium oxide was added. The molar ratio of calcium to tungsten: Ca/W is 2.7. Then, stirring was continued for 2 hours, and filtration was performed while maintaining the temperature to separate a filtrate and a cake. The cake was washed with a small amount of water in a range in which the concentration of alcohol amine did not fall below a predetermined concentration and which compensated for the water reduced by evaporation, and the washing liquid and the filtrate were combined. The pH of the liquid after cooling was 11.
Subsequently, 10 g of activated carbon was added to the filtrate, and the mixture was stirred for 10 minutes and filtered.
The concentration of tungsten contained in this filtrate was almost zero. When this solution was returned to the electrolytic cell to start electrolysis, electrolysis could be performed without any particular problem.

(Comparative example 1)
Cemented carbide scrap of the grade shown in Table 1 was electrolyzed under the same conditions as in Example 1 except that the amount of calcium oxide added was 15 g, and tungstic acid was recovered from the post-electrolysis solution. The molar ratio of calcium to tungsten: Ca/W is 0.8. The pH of the obtained liquid was 10.5. The liquid remained deeply colored without the activated carbon treatment, but it was reused without the activated carbon treatment because the activated carbon treatment causes a loss of tungstic acid. When the same regeneration treatment was repeated 10 times, the current efficiency gradually decreased, and it became 85% with the 10th liquid.

(Example 2)
As the anode of the electrolytic cell, 10 kg of cemented carbide scrap of the grade shown in Table 1 was placed in a titanium basket.
A titanium plate was used as the cathode of the electrolytic cell.
2 kg of monoethanolamine was used as the electrolytic solution to make 20 L with pure water. Next, a rectifier was connected, and electrolytic dissolution was carried out for 10 hours at a current density of 5 A/dm ² and a constant current of 100 A at a temperature of 70°C.

As a result, metallic cobalt was deposited on the surface of the titanium plate of the cathode. Further, tungsten was dissolved in the electrolytic solution to form a tungstic acid alcohol amine solution, and a residue was generated in the electrolytic solution. The amount of dissolved tungsten was 0.6 kg and the current efficiency was almost 100%.

Next, a resin packed tower was prepared by filling a tube having an inner diameter of 5 cm and a height of 20 cm with an anion exchange resin. Then, the above-mentioned tungstic acid alcohol amine solution was passed through the resin packed tower, and the solution was received in the container A. The space velocity SV of liquid passage was set to 10 hr ^-1 . The anion exchange resin used was one in which hydrochloric acid had been flowed in advance to replace it with chloride ions.
Subsequently, 5 L of pure water was poured into the resin packed tower for cleaning, and this liquid was also received in the container A.

3 L of this liquid was sampled, put into a 5 L rotating flask, and distilled under reduced pressure with a rotary evaporator. An oil bath was used for heating, and the pressure was reduced with a water pump. In the first stage, the temperature of the oil bath was set to 90° C. to evaporate water and impurities having a low boiling point, and the water was received in a receiving flask. When the liquid in the receiving flask is full, the distillation operation is stopped and discarded, and the distillation is continued again. Distillation was continued, and when the liquid amount in the rotary flask reached about 20%, the liquid in the rotary flask was transferred to the container B. The same operation was repeated to obtain about 5 L of the liquid in the container A concentrated about 5 times in volume ratio.
Subsequently, the temperature of the oil bath was set to 150° C., and about 3 L of the liquid in the container B was put in a rotary flask to reduce the pressure, and a portion containing monoethanolamine as a main component was recovered. Distillation was stopped when the concentration of the electrolytic solution proceeded and salt was deposited, or when the remaining amount of the solution reached about 200 ML. Similarly, the remaining liquid in the container B was treated, and the liquid containing monoethanolamine as a main component was recovered.
As a result of measuring the obtained liquid using a gas chromatograph, it contained 90% of monoethanolamine.
An electrolytic solution was prepared using the recovered solution so that the monoethanolamine content was 10 (V/V)%, the electrolytic solution was returned to the electrolytic cell, and electrolysis was started.

Claims (16)

Step 1A in which a raw material containing a valuable material containing tungsten is electrolyzed using an electrolytic solution containing alcohol amine and a part or all of the electrolytic solution after the electrolysis is extracted.
One or more selected from the group consisting of alkaline earth metal hydroxides and alkaline earth metal oxides are added to the electrolyte extracted in step 1A at a molar ratio of 1 to 5 times with tungsten, and solid-liquid mixing is performed. Step 1C of stirring and mixing in the state to adjust the pH to 9 to 13 ,
A step 1D of collecting the filtrate by filtering the electrolytic solution after the step 1C, and
Step 1E in which the filtrate obtained in the step 1D is reused as an electrolytic solution, and the residue generated in the step 1D is washed to collect the washing liquid.
A method for regenerating an alcohol amine-containing electrolyte containing: The method for regenerating an alcoholamine-containing electrolytic solution according to claim 1, further comprising a step 1F in which the filtrate obtained in the step 1D is treated with activated carbon. The method for regenerating an alcoholamine-containing electrolytic solution according to claim 1 or 2, further comprising a step 1G of separating impurities and concentrating an alcoholamine by subjecting the cleaning liquid recovered in the step 1E to a vacuum distillation treatment. The method for regenerating an alcoholamine-containing electrolytic solution according to claim 3, further comprising a step 1H in which the cleaning liquid is treated with activated carbon before or after the step 1G. For raw materials containing valuable materials containing tungsten, electrolysis is performed using an electrolytic solution containing alcohol amine, and liquid or tungsten before recovering tungsten from the electrolytic solution after performing the electrolysis is used. One or more selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides and alkaline earth metal oxides are added to the liquid after recovery in a molar ratio of 1 to 5 times that of tungsten. And 2) stirring and mixing to adjust the pH to 9-13 .
A step 2B of collecting the filtrate by filtering the electrolytic solution after the step 2A, and
Step 2C of separating impurities and distilling and recovering alcoholamine by subjecting the liquid obtained in Step 2B to vacuum distillation treatment
A method for regenerating an alcohol amine-containing electrolyte containing: The method for regenerating an alcoholamine-containing electrolytic solution according to claim 5, further comprising a step 2D in which the filtrate is treated with activated carbon before or after the step 2C. The heating temperature of the liquid in the vacuum distillation treatment of the step 2C is 60 to 120°C when components with boiling points up to 120°C are removed, and 120°C to 200°C when alcohol amine is recovered. A method for regenerating the alcohol amine-containing electrolytic solution described. Step 3A of electrolyzing a raw material containing a valuable material containing tungsten with an electrolyte containing alcohol amine, and extracting a part or all of the electrolyte after the electrolysis.
A step 3C of treating the liquid obtained in the step 3A by an ion exchange method to adsorb tungstic acid and/or polytungstic acid to an ion exchange resin, and collecting a liquid containing alcohol amine excluding tungsten.
One or more selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide and an alkaline earth metal oxide is added to the liquid obtained in the step 3C in a molar ratio of 1 to 5 with tungsten. Step 3E of adding twice and mixing/stirring to adjust the pH to 9 to 13 , and
Step 3F of separating impurities and distilling and recovering alcoholamine by subjecting the liquid obtained in Step 3E to vacuum distillation treatment.
A method for regenerating an alcohol amine-containing electrolyte containing: The method further includes a step 3B of adjusting the viscosity by adding water to the electrolytic solution extracted in the step 3A, if necessary.
The method for regenerating an alcoholamine-containing electrolytic solution according to claim 8, wherein the electrolytic solution after adjusting the viscosity is used as a solution to be treated by the ion exchange method in the step 3C. The method further includes a step 3D of washing the ion exchange resin having adsorbed tungstic acid and/or polytungstic acid obtained in the step 3C with water to recover a washing liquid,
The method for regenerating an alcoholamine-containing electrolytic solution according to claim 8 or 9, wherein the recovered cleaning liquid is used as a liquid for performing vacuum distillation treatment in the step 3E. The method for regenerating an alcoholamine-containing electrolytic solution according to any one of claims 8 to 10, further comprising a step 3G in which the solution is treated with activated carbon in a stage before or after the step 3F. The heating temperature of the liquid in the vacuum distillation treatment of the step 3F is 60 to 120°C when components having a boiling point of up to 120°C are removed, and 120°C to 200°C when alcohol amine is recovered. A method for regenerating the alcohol amine-containing electrolytic solution according to any one of items. 13. The alkali metal hydroxide is sodium hydroxide or potassium hydroxide, the alkaline earth metal hydroxide is calcium hydroxide, and the alkaline earth metal oxide is calcium oxide. The method for regenerating an alcoholamine-containing electrolytic solution according to the item 1. The alcohol amine is methanol amine, ethanol amine, propanol amine, butanol amine, pentanol amine, dimethanol amine, diethanol amine, trimethanol amine, methyl methanol amine, methyl ethanol amine, methyl propanol amine, methyl butanol amine, ethyl methanol amine 14. Ethylethanolamine, ethylpropanolamine, dimethylmethanolamine, dimethylethanolamine, dimethylpropanolamine, methyldimethanolamine, methyldiethanolamine and diethylmethanolamine, which is one or more selected from the group consisting of: A method for regenerating the alcohol amine-containing electrolytic solution according to any one of items. The alcohol amine is triethanolamine, dibutanolamine, dipentanolamine, dihexanolamine, tripropanolamine, tributanolamine, methyldipropanolamine, methyldibutanolamine, methyldihexanolamine, ethyldipropanolamine, The method for regenerating an alcoholamine-containing electrolytic solution according to any one of claims 1 to 13, which is at least one selected from the group consisting of ethyldibutanolamine and butyldiethanolamine. The alcohol amine is heptanolamine, decanolamine, nonanolamine, decanolamine, methylhexanolamine, methyloctanolamine, ethylpentanolamine, hexyldiethanolamine, dimethylhexanolamine, lauryldiethanolamine, benzylethanolamine and phenylethanol. The method for regenerating an alcoholamine-containing electrolyte according to any one of claims 1 to 13, wherein the method is one or more selected from the group consisting of amines.