KR101163557B1 - High efficient uranium recovery method through high speed leaching - Google Patents

Abstract

PURPOSE: A high-efficiency uranium recovery method using high-speed leaching is provided to improve leaching and adsorption efficiencies by injecting an adsorbing agent and applying ultrasonic waves at the same time as leaching. CONSTITUTION: A high-efficiency uranium recovery method using high-speed leaching comprises the steps of: pulverizing black slate including uranium to prepare black slate powder with an average grain size of 20-250 meshes(S110), injecting the black slate powder including uranium, leaching solution, and an absorbing agent into a reactor at the same time and processing leaching and absorption for 0.1-3 hours(S120), and extracting the leaching solution from the reactant and collecting the uranium ion adsorbed in the adsorbing agent of the reactant(S130).

Description

High efficiency uranium recovery method through high speed leaching {HIGH EFFICIENT URANIUM RECOVERY METHOD THROUGH HIGH SPEED LEACHING}

The present invention relates to a uranium recovery method, and more particularly, to a high-efficiency uranium recovery method that can improve the leaching rate through the addition of an adsorbent while simultaneously adding uranium-containing black slate rock to the leaching solution.

Uranium extracted through the leaching reaction from the mineral containing uranium is subjected to a process of adsorption and purification by ion exchange resin, in this case the column method has been the mainstream.

In this column method, the uranium-leached leaching solution is introduced into the reactor in a vertical direction. This requires a solid / liquid separation step of separating the residue remaining in the leaching solution after the leaching reaction.

In recent years, as part of avoiding the inherent problems of columnar systems, uranium is leached from the raw material to form a thick slurry, and then ion exchange resins are used to directly adsorb uranium from the slurry rather than a clear, rich leach solution. Resin-in-pulp methods have been developed.

However, in the case of such a resin-in-pulp method, uranium ion exchange adsorption is performed by agitating the slurry containing the uranium leaching solution and the ion exchange resin mixed into the reactor to be properly mixed, and this process takes about tens to hundreds of hours. Because of the very slow progression of uranium ion exchange adsorption time is very long, there is a problem that the adsorption rate is very low.

Related prior art documents include Korean Patent Registration No. 10-1984-0001372 (published on September 21, 1984), which discloses a method for recovering uranium from wet method phosphoric acid.

An object of the present invention is to provide a high-efficiency uranium recovery method that can improve the leaching rate and omit the solid / liquid separation process by adding the adsorbent at the same time as the leaching process.

Another object of the present invention is to provide a high-efficiency uranium recovery method through the high-speed leaching that can be improved by leaching the ultrasonic wave while applying the adsorbent simultaneously with the leaching process.

According to a first embodiment of the present invention, a high-efficiency uranium recovery method through high-speed leaching comprises the steps of: (a) crushing black slate rock containing uranium to prepare black flake plate powder containing uranium; (b) adding the uranium-containing black dot powder, a leaching solution, and an adsorbent into a reaction tank to perform leaching and adsorption reactions; And (c) extracting the leaching solution from the leaching and reacting reactants, and recovering uranium ions adsorbed on the adsorbent among the reactants from which the leaching solution has been removed.

According to another aspect of the present invention, there is provided a method of recovering high-efficiency uranium through high-speed leaching, comprising: (a) crushing a black slate rock containing uranium to prepare a black slate powder containing uranium; (b) applying ultrasonic waves while adding the uranium-containing black plate powder, a leaching solution, and an adsorbent into a reaction tank while leaching and adsorbing; And (c) extracting the leaching solution from the leaching and reacting reactants, and recovering uranium ions adsorbed on the adsorbent among the reactants from which the leaching solution has been removed.

In the present invention, by adding the adsorbent and simultaneously adsorbing uranium ions to the leaching reaction, the leaching rate can be improved and the solid / liquid separation process can be omitted.

In addition, the present invention can further improve the leaching and adsorption efficiency by applying ultrasonic waves while putting the adsorbent at the same time as the leaching process.

1 is a process flow chart showing a high efficiency uranium recovery method through a high-speed leaching according to a first embodiment of the present invention.
2 is a process schematic diagram showing a leaching / recovering reaction according to the first embodiment of the present invention.
Figure 3 is a process schematic diagram showing the leaching / adsorption reaction process of the high efficiency uranium recovery method through a high-speed leaching according to the second embodiment of the present invention.
4 is a graph showing the results of ICP mass spectrometry according to Example 1 and Comparative Example 1. FIG.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and those skilled in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, a high efficiency uranium recovery method through high speed leaching according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a process flow chart showing a high efficiency uranium recovery method through a high-speed leaching according to a first embodiment of the present invention, Figure 2 is a process schematic diagram showing the leaching / adsorption reaction process of FIG.

1 and 2, the high-efficiency uranium recovery method through a high-speed leaching according to the first embodiment of the present invention is black plate powder preparation step (S110), leaching / adsorption reaction step (S120) and uranium ion recovery step ( S130).

Black dot powder preparation

In preparing the black plate powder (S110), the black plate plate cancer containing uranium is pulverized to prepare a black plate powder containing uranium.

At this time, it is preferable that the black dot plate powder containing uranium is pulverized to have an average particle size of 20 to 250 mesh. When the average particle size of the black plate powder is less than 20 mesh, there is a problem in that the grinding cost is excessively consumed. On the contrary, when the average particle size of the black dot powder exceeds 250 mesh, the leaching effect may be insignificant.

Leaching / adsorption reaction

In the leaching / adsorption step (S120), black plate powder, a leaching solution, and an adsorbent containing uranium are introduced into the reaction tank 100.

The leaching solution may be a solution containing water, sulfuric acid, oxidizing agent and iron sulfate. At this time, the leaching solution may be added in about 1 to 10g of sulfuric acid, 30 to 40g of oxidizing agent and 2 to 5g of iron sulfate. At this time, when the amount of iron sulfate added is less than 2 g per 1 liter of water, the effect of adding iron sulfate cannot be properly exhibited. On the contrary, when the addition amount of iron sulfate exceeds 5g with respect to 1L of water, the synergistic effect compared to the addition of iron sulfate is insignificant and therefore it is not economical.

In addition, the black plate powder may be added in an amount of about 1 to 40 g based on 1 L of water.

In this step, as the adsorbent, an anion ion exchange resin may be used, and specifically, it may be selected from porous synthetic resins including strong basic and weak basic anion exchange resins. As such a porous synthetic resin, for example, Lanxess MP 600 may be used. At this time, the adsorbent may be added to about 2 ~ 10g per 1L of water.

Meanwhile, the redox potential electrode 110, the pH electrode 120, the sulfuric acid inlet 130, the oxidant inlet 140, the iron sulfate inlet 150, and the adsorbent inlet 160 are disposed in the reactor 100. Can be.

At this time, the pH of the mixed solution 105 of the black plate powder, the leach solution and the adsorbent is controlled to 1-2, and the oxidation reduction potential (ORP) is appropriately controlled to 450 to 600mV. At this time, the pH is controlled by sulfuric acid, the redox potential can be adjusted by the input amount of the oxidizing agent.

Manganese dioxide (MnO ₂ ) may be used as the oxidizing agent. And, leaching / adsorption reaction is preferably carried out at 10 ~ 50 ℃, the mixing is preferably stirred at 250 ~ 550rpm.

As such, the mixed solution 105 of the black plate powder, the leaching solution and the adsorbent introduced into the reaction tank 100 is rotated by the stirrer 170 at a speed such that it does not overflow from the reaction tank 100 for a predetermined time. It is preferred to stir for a while.

In addition, the leaching and adsorption reaction time is preferably carried out for 0.1 to 3 hours. In this case, in the case of the present invention, the leaching and adsorption reaction time may be shortened within 3 hours due to the addition of the anion ion exchange resin, which is an adsorbent, simultaneously with the leaching reaction, which will be described later.

In this step, when the black plate powder containing uranium is leached with sulfuric acid and iron sulfate, UO ₂ is oxidized to UO ₂ ²⁺ by Fe ^3+, where the trivalent iron ions contained in the black plate powder are leached. You will participate in

That is, when a leaching reaction occurs in trivalent iron ions coexisting in a mixed solution in which water, sulfuric acid, an oxidizing agent and iron sulfate are added to the black plate powder containing uranium, a reaction such as the following Chemical Formulas 1 and 2 may occur. Can be.

[Formula 1]

FeS + 4O ₂ + 2H ₂ SO ₄ → FeSO ₄ + 2H ₂ SO ₄

[Formula 2]

2FeS ₂ + 7O ₂ + 2H ₂ O → 2FeSO ₄ + 2H ₂ SO ₄

The dissolved FeSO ₄ is Fe ₂ (SO ₄ ) ₃ by the oxidizing agent, a reaction such as the following Chemical Formulas 3, 4, and 5 may occur.

(3)

4FeSO ₄ + O ₂ + 2H ₂ SO ₄ → 2Fe ₂ (SO ₄ ) ₃ + 2H ₂ O

[Formula 4]

2FeSO ₄ + MnO ₂ + 2H ₂ SO ₄ → Fe ₂ (SO ₄ ) ₃ + MnSO ₄ + 2H ₂ O

[Chemical Formula 5]

UO ₂ + Fe ₂ (SO ₄ ) ₃ → UO ₂ SO ₄ + 2FeSO ₄

And, the leaching reaction of uranium may occur a reaction as shown in the formula (6).

[Formula 6]

UO ₂ + 2Fe ³⁺ → UO ₂ ²⁺ + 2Fe ²⁺

Therefore, Fe ₂ (SO ₄ ) ₃ is to dissolve the uranium contained in the black plate powder.

At this time, in the present invention, the uranium ions (UO ₂ ²⁺ ) dissolved through the leaching reaction are combined with SO ₄ ^2- and exist in the solution in an anionic form {UO ₂ (SO ₄ ) ₂ ^2- }, and the uranium complex ion { UO ₂ (SO ₄ ) ₂ ^2- } is adsorbed to the anion adsorbent in real time.

In this case, since the reaction which adsorbs uranium ion simultaneously with a leaching reaction takes place, the tendency to continuously produce uranium ion becomes strong. That is, since the number of uranium ions dissolved in the leaching reaction is continuously decreased due to the adsorption to the anion ion exchange resin as the adsorbent, the tendency to produce uranium ions quickly becomes stronger, thereby improving the leaching rate. As a result, in the present invention, the leaching reaction time can be shortened.

Uranium Ion Recovery

In the uranium ion recovery step (S130), after extracting the leach solution from the leaching and the reactant reacted, the uranium ions adsorbed to the adsorbent in the leachate is removed.

In the uranium ion recovery step (S130), the leaching solution is filtered and removed by sieve to obtain a reactant that is leached and adsorbed, that is, an adsorbent to which uranium ions are adsorbed, and then stripped to remove the adsorbent in the reactant. Only the uranium ions adsorbed on can be recovered. That is, the reactant reacted with leaching and adsorption is left in the sieve, and the leaching solution and residue pass through the sieve and are discharged to the outside.

The high efficiency uranium recovery method through the high-speed leaching according to the first embodiment of the present invention can improve the leaching rate and omit the solid / liquid separation process by adding an adsorbent simultaneously with the leaching process.

In addition, in the case of the resin-in-pulp method according to the related art, in the solid / liquid separation process, there is a problem in that the adsorption efficiency is lowered because the residue is not adsorbed to the adsorbent. Since ion exchange adsorption is performed at, the ion exchange adsorption efficiency can be improved.

On the other hand, Figure 3 is a schematic diagram showing the leaching / adsorption reaction process of the high-efficiency uranium recovery method through a high-speed leaching according to a second embodiment of the present invention.

In this case, the high-efficiency uranium recovery method through the high-speed leaching according to the second embodiment of the present invention may be substantially the same as the first embodiment of the present invention. However, the high-efficiency uranium recovery method through high-speed leaching according to the second embodiment of the present invention is characterized in that the ultrasonic wave is applied in the leaching / adsorption reaction step.

3, in the case of a high-efficiency uranium recovery method through a high-speed leaching according to the second embodiment of the present invention, the black plate powder, leach solution and adsorbent containing uranium in the reaction tank 200 in the leaching / adsorption reaction step It is characterized by applying ultrasonic waves while the leaching reaction and adsorption reaction.

At this time, the ultrasonic wave preferably applies a frequency of 10 to 50KHz and an output power of 1 to 10W. If the frequency of the ultrasonic wave is less than 10KHz, or the output voltage is less than 1W, the cavitation effect due to the application of the ultrasonic wave is insignificant, so that the leaching and adsorption reaction may not be performed smoothly. On the contrary, when the frequency of the ultrasonic waves is 50 KHz or more, or the output voltage exceeds 10 W, it may cause a problem that the adsorbent is destroyed due to excessive ultrasonic application.

As such, when ultrasonic waves are applied simultaneously with the leaching and adsorption reaction, when ultrasonic waves are applied to the mixed solution 205 filled in the reaction tank 200, when a predetermined time elapses, the bubble collapses instantly. Locally, temperatures of 5000K, pressures of around 1000 bar and heating / cooling ratios of 10 ¹⁰ K / s have extreme conditions. For this reason, the chemical reactivity of the mixed solution 205 can be significantly increased.

As such, when the ultrasonic wave is continuously applied during the leaching / adsorption reaction step, the leaching speed is increased due to the mixing effect by the cavitation and the increase of the effective collision frequency, thereby maximizing the leaching and adsorption effect of uranium. There is an advantage that can shorten the leaching and adsorption reaction time.

In particular, during the leaching / adsorption reaction step, it is preferable to insert the tip of the ultrasonic device 280 into the reaction vessel 200 and directly irradiate the ultrasonic waves. In this case, the intensity of the ultrasonic waves applied to the mixed solution 205 is strong. As an advantage, there is an advantage that can maximize the ultrasonic effect.

The high-efficiency uranium recovery method through high-speed leaching according to the second embodiment of the present invention has an advantage of further improving leaching and adsorption efficiency by applying ultrasonic waves while adding an adsorbent simultaneously with the leaching process.

Example

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

Example 1

20 g of black slate rock containing uranium was ground to 60 mesh to prepare a black slate powder containing uranium. Thereafter, 20 g of the black plate powder containing uranium was charged with 1000 ml of distilled water, 3 g of iron sulfate, and 5 g of anion ion exchange resin {UO ₂ (SO ₄ ) ₂ ^2- }, followed by stirring at 400 rpm to leach and adsorb the reaction. I was. At this time, 5g of sulfuric acid and 36g of manganese dioxide were further added to maintain a pH of 2.0 and a redox potential of 550mV. The total leaching and adsorption reaction was carried out for 4 hours, samples were taken every 30 minutes and filtered, and the mixed solution was analyzed by ICP to measure the uranium leaching rate.

Comparative Example 1

20 g of black slate rock containing uranium was ground to 60 mesh to prepare a black slate powder containing uranium. Thereafter, 20 g of the black plate powder containing uranium was charged with 1000 ml of distilled water and 3 g of iron sulfate into the reactor, followed by stirring at 400 rpm to leach. At this time, 5 g of sulfuric acid and 36 g of manganese dioxide were added to maintain a pH of 2.0 and a redox potential of 550 mV. The total leaching reaction was carried out for 4 hours, samples were taken every 30 minutes and filtered, and the mixed solution was analyzed by ICP to measure the uranium leaching rate.

Table 1 shows the results of measuring the uranium leaching rate for the samples according to Example 1 and Comparative Example 1, Figure 4 is a graph showing the results of ICP mass spectrometry according to Example 1 and Comparative Example 1.

[Table 1]

Referring to Table 1 and Figure 4, in the case of Example 1 to which the anion ion exchange resin was added at the same time as the leaching reaction, the leaching rate was generally higher than that of Comparative Example 1 not added anion ion exchange resin during the leaching reaction You can check it.

Based on the above experimental results, it can be seen that the addition of anion ion exchange resin at the same time as the leaching reaction can reduce the leaching time due to the increase of leaching rate.

Although the above has been described with reference to the embodiments of the present invention, various changes and modifications can be made at the level of those skilled in the art. These changes and modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

S110: black plate powder preparation step
S120: leaching / adsorption reaction step
S130: Uranium Ion Recovery Step
100: reaction tank 110: redox potential electrode
120: pH electrode 130: sulfuric acid inlet
140: oxidant inlet 150: iron sulfate inlet
160: adsorbent inlet 170: agitator

Claims (11)

(a) pulverizing the black slate rock containing uranium to prepare a black slate powder containing uranium having an average particle size of 20 to 250 mesh;
(b) simultaneously adding the uranium-containing black plate powder, a leaching solution and an adsorbent into a reaction tank to perform leaching and adsorption reactions for 0.1 to 3 hours; And
(c) extracting the leaching solution from the leaching and reacting reactants, and recovering uranium ions adsorbed on the adsorbent among the reactants from which the leaching solution has been removed;
In the step (b), the black plate powder containing the uranium is mixed with the leaching solution to produce uranium ions while leaching, and the generated uranium ions are adsorbed on the adsorbent in real time to tend to produce uranium ions. High efficiency uranium recovery method through high-speed leaching, characterized in that to increase the leaching rate.
delete delete The method of claim 1,
The adsorbent
High efficiency uranium recovery method through high-speed leaching, characterized in that the anion ion exchange resin.
The method of claim 4, wherein
The anion ion exchange resin
A high efficiency uranium recovery method through high speed leaching, characterized by adsorbing UO ₂ (SO ₄ ) ₂ ^2- .
The method of claim 1,
The leaching solution is
A high efficiency uranium recovery method through high speed leaching, comprising water, sulfuric acid, oxidizing agent and iron sulfate.
The method of claim 6,
In the step (b)
High efficiency uranium recovery method through a high-speed leaching characterized in that the pH is controlled to 1 ~ 2, the redox potential is controlled to 450 ~ 600mV.
The method of claim 7, wherein
The pH is controlled by sulfuric acid, and the redox potential is controlled by a high-efficiency uranium recovery method characterized in that it is adjusted by the input amount of the oxidant.
(a) pulverizing the black slate rock containing uranium to prepare a black slate powder containing uranium having an average particle size of 20 to 250 mesh;
(b) simultaneously applying the uranium-containing black dot powder, a leaching solution, and an adsorbent into a reaction tank and applying ultrasonic waves while leaching and adsorption reaction for 0.1 to 3 hours; And
(c) extracting the leaching solution from the leaching and reacting reactants, and recovering uranium ions adsorbed on the adsorbent among the reactants from which the leaching solution has been removed;
In the step (b), the black plate powder containing the uranium is mixed with the leaching solution to produce uranium ions while leaching, and the generated uranium ions are adsorbed on the adsorbent in real time to tend to produce uranium ions. High efficiency uranium recovery method through high-speed leaching, characterized in that to increase the leaching rate.
10. The method of claim 9,
In the step (b)
The ultrasound is
High efficiency uranium recovery method through high-speed leaching, characterized in that applying a frequency of 10 ~ 50KHz and 1 ~ 10W output power.
10. The method of claim 9,
The adsorbent
High efficiency uranium recovery method through high-speed leaching, characterized in that the anion ion exchange resin.

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