JP2007177278A - Fluorine-adsorbing-desorbing agent for use in removing fluorine from process liquid for wet zinc-smelting process, and method for removing fluorine with the use of the fluorine-adsorbing-desorbing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for removing fluorine that has been accumulated in a process liquid for a wet zinc-smelting process, from the liquid, which has been prepared by dissolving a zinc-containing substance containing a high concentration of fluorine. <P>SOLUTION: A fluorine-adsorbing-desorbing agent employs an aluminum compound of a solid body. The concentration of fluorine in the process liquid for the wet zinc-smelting process can be controlled into a target range by making the aluminum-based fluorine-adsorbing-desorbing agent adsorb fluorine. The aluminum-based fluorine-adsorbing-desorbing agent can be regenerated by desorption treatment and can be repeatedly used. Thereby, an inexpensive raw material can be used for the wet zinc-smelting process, and a total cost in the wet zinc-smelting process can be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for removing fluorine from a process liquid for wet zinc smelting that contains fluorine by using a fluorine-containing zinc-containing material as a melting raw material, and a fluorine adsorbent / desorbent that can be used in the method (the present invention) Refers to a substance that has the ability to adsorb fluorine in an aqueous solution and can be reused by desorbing the adsorbed fluorine by subjecting the aqueous solution to fluorine desorption after solid-liquid separation. .) Specifically, the present invention relates to an aluminum-based fluorine adsorbent / desorbent that can be repeatedly used by desorbing and regenerating after adsorbing fluorine in an aqueous solution, and a fluorine removal method using the aluminum-based fluorine adsorbent / desorbent.

  In a general wet zinc smelting process, zinc sulfide ore, which is a raw material, is roasted to oxidize and desulfurize zinc sulfide, which is the main component, to obtain a sinter containing zinc oxide as the main component. Dissolved and leached with tail liquor (sulfuric acid zinc sulfate solution that has undergone electrowinning of metallic zinc in a zinc electrolyzer) to form zinc leachate, and impurities that adversely affect the electrowinning process from this zinc leachate (mainly ionized rather than zinc) The composition of the zinc electrolyte is adjusted using the cleaning liquid from which the metal having a small tendency is removed, and is circulated in the electrolysis process. Then, in a zinc electrolytic cell installed in the circulation process, the lead alloy is used as an anode, and an aluminum plate is used as a cathode, and zinc is electrodeposited on the cathode plate by an electrolysis method. The purity is 99.99%. Electro zinc has been manufactured. In the present invention, these electrolytic tail solution, zinc electrolyte solution, zinc leaching solution and cleaning solution related to the wet zinc smelting process are collectively referred to as a process solution for wet zinc smelting.

  On the other hand, in recent years, zinc-containing materials such as crude zinc oxide obtained by reprocessing the steelmaking dust discharged in the steelmaking process at the steelworks and the zinc soot generated in the galvanizing process are mixed with the aforementioned sinter. The method of use has also been adopted.

  As described above, since the zinc-containing material is non-sulfide, there is no need for roasting, and thus the manufacturing cost in the wet zinc smelting process can be reduced, but it contains a halogen element. It is also well known that it can cause problems in the wet zinc smelting process. Although the harmful halogen elements are not limited, the present invention focuses on fluorine which causes a particularly serious problem in the hydrozinc smelting.

  By the way, although it is the tolerance | permissible_range of the fluorine concentration in zinc electrolyte solution, generally 20 mg / l is made into the upper limit. Beyond this, corrosion of the aluminum plate, which is the electrode for electrodepositing zinc, becomes severely corrosive, and automatic machines tend to generate so-called contact plates that cannot be peeled off from the aluminum plate, which is the cathode plate. It is. As a result, in order to maintain the continuous operation of the electrolysis process, it is necessary to process the contact plate offline and replace it with an alternative cathode plate. It can happen. In addition, when the adhesive plate is processed manually, the life of the aluminum plate that should be used repeatedly is shortened due to corrosion and mechanical damage, resulting in an increase in manufacturing costs and the merit of using inexpensive raw materials. In fact, it can be counterproductive.

  Therefore, several methods have been proposed as methods for preventing fluorine from being mixed into the zinc electrolyte. Patent Document 1 discloses a total of three methods. The first method is a method in which water is washed at the stage of a zinc source (zinc raw material) as a method for preventing fluorine from being mixed into the zinc electrolyte (referred to as “conventional method 1”). The second method is a method of removing fluorine by sulfated roasting (referred to as “conventional method 2”). In the third method, the zinc electrolytic smelting process is divided into two stages. In the first stage, a predetermined amount of zinc is deposited using an acidic zinc sulfate solution that does not contain fluorine ions. This is a zinc two-step electrowinning method (hereinafter referred to as “conventional method 3”) in which zinc is further deposited on zinc that has already been deposited from the acidic zinc sulfate solution.

  Patent Document 2 discloses a fluorine removal method using cerium hydroxide as a method for directly removing fluorine from a zinc electrolyte (referred to as “conventional method 4”).

  Patent Document 3 (referred to as “Conventional Method 5”) and Patent Document 4 (referred to as “Conventional Method 6”) disclose a method for removing fluorine in the wastewater treatment process.

JP-A-4-22189 JP 2002-105685 A JP-A-6-262170 Japanese Patent Laid-Open No. 10-137744

  However, since the chemical bonding state of fluorine contained in the zinc-containing material is not always water-soluble only with water washing, which is the method of the conventional method 1, sufficient removal of fluorine cannot be expected so much.

  In addition, the conventional method 2 requires a special process called sulfation roasting, so additional equipment is necessary. Therefore, the running cost is surely increased, and the economic efficiency is considerably impaired.

  Furthermore, in the conventional method 3, it is necessary to divide the electrowinning process into two stages, so at least two sets of similar electrowinning equipment are required, and although the adverse effects of fluorine can be avoided, the capital investment cost for the smelting equipment increases, and the process management However, the increase in cost is inevitable due to the complexity.

  Furthermore, in the conventional method 4, the price of cerium hydroxide having a function of adsorbing fluorine is high, and the shift to actual operation is difficult due to the problem of running cost.

  That is, in the conventional methods 1 to 4 shown in Patent Document 1 and Patent Document 2, it is difficult to reduce fluorine to an expected level even if the raw material cost can be suppressed, In addition, it is necessary to deploy additional equipment to the conventional equipment in order to perform simple processing, so it is necessary to review the equipment layout, and it is necessary to use expensive additives. Therefore, it was difficult to put it into practical use.

  The conventional method 5 shown in Patent Document 3 and the conventional method 6 shown in Patent Document 4 are fluorine removal techniques applied to wastewater treatment. First, calcium is allowed to act on calcium fluoride. Then, the low concentration fluorine remaining in the liquid is adsorbed on aluminum hydroxide and removed.

  These methods are difficult to apply because a large amount of calcium sulfate is generated when a process solution for wet zinc smelting with a high sulfuric acid concentration is used. In addition, aluminum hydroxide as an adsorbent has undergone a process of once being dissolved and regenerated in order to filter off the fluoride that has become a solid, and cannot be reused as it is. Therefore, the composition of the treatment process is different because the liquid quality is different, and the method of desorption of fluorine is also different, so that it cannot be applied to the wet zinc smelting process intended by the present invention.

  As can be seen from the above, the cost reduction effect by using zinc-containing materials such as crude zinc oxide containing fluorine, which is an inexpensive raw material, should not be offset by the cost increase due to other additional processes and process troubles. It was a big proposition for the zinc smelter. In other words, there is a need for a method for removing fluorine from a process liquid for wet zinc smelting that contains fluorine, which is suitable for wet zinc smelting that does not require investment such as the addition of large-scale equipment and requires low running costs. It has come.

  As a result of diligent research to solve the above problems, the inventors of the present invention accumulated in a process solution for wet zinc smelting when a zinc-containing material containing fluorine was used as a zinc source for preparing a zinc electrolyte. Fluorine adsorbing / desorbing agent according to the present invention that can adsorb and remove fluorine that has been adsorbed and then desorb and reuse the adsorbed fluorine, and a process liquid for wet zinc smelting containing fluorine using the fluorine adsorbing / desorbing agent They found a method to remove fluorine from the water.

  The means for solving the problem will be described in detail below.

  The present invention provides an aluminum-based fluorine adsorbent / desorbent which is an aluminum compound, which is a fluorine adsorbent / desorbent for adsorbing and removing fluorine from a process liquid for hydrometallurgical smelting containing fluorine.

The aluminum-based fluorine adsorbent / desorbent is a basic aluminum sulfate-based aluminum compound (Al (SO ₄ ) _x (OH) _y (x, y are arbitrary real numbers)) and (AlO _a (OH) _b (SO ₄ ) _c (H 2 O) _d (a, b, c, d are arbitrary real numbers)) is preferably one or two selected from.

  It is also preferable that the aluminum-based fluorine adsorbent / desorbent is aluminum oxyhydroxide (AlOOH).

  The aluminum oxyhydroxide is more preferably boehmite (α-AlOOH) or diaspore (β-AlOOH).

It is also preferable that the aluminum-based fluorine adsorbent / desorbent is aluminum hydroxide (Al (OH) ₃ ).

And it is more preferable that the aluminum hydroxide is gibbsite (α-Al (OH) ₃ ) or bayerite (Bayerite: β-Al (OH) ₃ ).

  It is also preferable that the aluminum-based fluorine adsorbent / desorbent is aluminum oxide.

More preferably, the aluminum oxide is alumina (Allumina: Al ₂ O ₃ ).

  Furthermore, the aluminum-based fluorine adsorbent / desorbent according to the present invention has a pH region that adsorbs fluorine of more than pH 3.0 and less than pH 7.0, and a pH region that desorbs fluorine of pH 7.0 or more or pH 3.0. The following regions are preferred.

The present invention is a method for removing fluorine from a process liquid for wet zinc smelting containing fluorine, which includes the following steps a to e, and includes fluorine removal using an aluminum-based fluorine adsorbent / desorbent: Provide a method.
Step a. Fluorine adsorption step of adsorbing fluorine contained in the process liquid for wet zinc smelting to the aluminum-based fluorine adsorbent / desorbent step b. First solid-liquid separation step for solid-liquid separation of the treatment liquid obtained in step a Step c. Fluorine desorption step of desorbing fluorine from the fluorine adsorbent / desorbent adsorbing fluorine, which is the solid content separated in step b, step d. Second solid-liquid separation step for solid-liquid separation of the desorbed liquid obtained in step c

  Furthermore, it is also preferable to add a step of repeatedly using the solid content (aluminum-based fluorine adsorbent / desorbent) recovered in step d in step a.

  And step a. The amount of the aluminum-based fluorine adsorbent / desorbent to be added in the process is 100 to 300 times as the amount of aluminum (unit: mg) relative to the amount of fluorine (unit: mg) in the process liquid for hydrozinc smelting process. It is preferable to add.

  And said process a. In the process of adsorbing fluorine in the wet zinc smelting process liquid containing fluorine to the aluminum-based fluorine adsorbent / desorbent, the pH of the wet zinc smelting process liquid should be in the region of more than 3.0 and less than 7.0. Is preferred.

  Further, the step a. In the above, when the fluorine of the wet zinc smelting process liquid containing fluorine is adsorbed to the aluminum-based fluorine adsorbent / desorbent, the pH of the wet zinc smelting process liquid may be in the range of 4.0 or more and 6.0 or less. It is more preferable.

  And said process c. In this case, it is preferable that the pH of the desorption solution is in the region of 3.0 or lower when desorbing fluorine from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b.

  Further, the step c. In this case, the pH of the desorption solution is more preferably 2.0 or more and 3.0 or less when desorbing fluorine from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. is there.

  And said process c. In this case, it is preferable to wash with water in the region of more than 3.0 and less than 5.0 before desorbing fluorine from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. .

  The step c. In this case, when desorbing fluorine from the aluminum-based fluorine adsorbing / desorbing agent adsorbing fluorine separated in step b, it is preferable that the pH of the desorption solution is in the region of 7.0 or more.

  Further, the step c. In this case, it is more preferable that the pH of the desorption solution is 9.5 or more and 10.5 or less when desorbing fluorine from the aluminum-based fluorine adsorbing / desorbing agent adsorbing fluorine separated in step b. is there.

  And said process d. It is preferable to add a water-soluble alkaline earth metal compound to the desorbed solution containing desorbed fluorine obtained in (1) to precipitate and separate fluorine as an alkaline earth compound.

  Using the fluorine adsorbent / desorbent according to the present invention, the fluorine adsorbent adsorbs fluorine in the wet zinc smelting process liquid containing fluorine before the electrowinning of metallic zinc in the zinc electrolytic cell, thereby The fluorine content in the liquid can be reduced to a predetermined value or less. And since the said fluorine adsorbent which adsorb | sucked this fluorine can be reproduce | regenerated by desorption operation and can be used repeatedly, the fluorine in the process liquid for wet zinc smelting can be removed without a significant cost increase.

  As the best mode for carrying out the present invention, <fluorine adsorption / desorption agent> and <fluorine removal method using the fluorine adsorption / desorption agent> for removing fluorine from the process liquid for hydrometallurgical smelting containing fluorine Will be sequentially described below.

  The present invention is a fluorine adsorbent / desorbent for adsorbing and removing fluorine from a hydrous zinc smelting process liquid, wherein the fluorine adsorbent / desorbent is an aluminum compound. Provide the agent. This aluminum-based fluorine adsorbent / desorbent is a solid substance among the aluminum compounds having fluorine adsorption ability, and can be repeatedly reused because fluorine can be eliminated by a simple operation. By selecting and using this, the initial cost and running cost of the defluorination treatment can be suppressed.

In the present invention, the aluminum-based fluorine adsorbent / desorbent is a basic aluminum sulfate-based aluminum compound (Al (SO ₄ ) _x (OH) _y (x and y are arbitrary real numbers)) and (AlO _a (OH) _b (SO ₄ ) _c (H 2 O) _d (where a, b, c and d are arbitrary real numbers)) or both are preferred. This basic aluminum sulfate-based aluminum compound has many OH groups as seen in the chemical formula, and therefore can substitute a lot of fluorine, and because of its large molecular weight, its solubility in water after substitution is low. The characteristics also enhance the fluorine removal effect.

  The aluminum-based fluorine adsorbent / desorbent is preferably aluminum oxyhydroxide (AlOOH), and the aluminum oxyhydroxide is boehmite (α-AlOOH) or diaspore (β-AlOOH). More preferred. This aluminum oxyhydroxide is located between aluminum hydroxide and alumina, and is preferable because it is difficult to dissolve in water in the pH range preferred in the present invention.

The aluminum-based fluorine adsorbent / desorbent is preferably aluminum hydroxide (Al (OH) ₃ ), and the aluminum hydroxide is either gibbsite (α-Al (OH) ₃ ) or vialite (β- More preferred is Al (OH) ₃ ). This aluminum hydroxide is preferred because it has the most OH groups in the aluminum compound.

The aluminum-based fluorine adsorbent / desorbent is preferably aluminum oxide, and the aluminum oxide is more preferably alumina (Al ₂ O ₃ ). Aluminum oxide is preferable because it does not dissolve in water while having an OH group on the surface by reaction with moisture in the air atmosphere even in an aqueous solution or before use.

  In the present invention, the aluminum-based fluorine adsorbent / desorbent adsorbs the fluorine in an acidic region exceeding pH 3.0 and less than pH 7.0, and desorbs fluorine in a region of pH 7.0 or higher or pH 3.0 or lower. It is preferable that This pH range is the range in which zinc in the process liquid for wet zinc smelting exists as ions, and at the same time, each aluminum-based fluorine adsorbent / desorbent has OH groups having an ion exchange function with F. This is the pH range where it can exist stably. Further, it almost coincides with the pH range of the acidic zinc sulfate solution of high-concentration zinc, and is particularly suitable for defluorination from a concentrated solution (zinc oxide leaching solution or cleaning solution) for adjusting the zinc concentration.

The present invention provides a method for removing fluorine from a process liquid for hydrometallurgical smelting containing fluorine, comprising the following steps a to d.
Step a. Fluorine adsorption process for adsorbing fluorine in hydrozinc smelting process liquid to aluminum-based fluorine adsorption / desorption agent,
Step b. A first solid-liquid separation step for solid-liquid separation of the treatment liquid obtained in step a,
Step c. A fluorine desorption step of desorbing fluorine from the fluorine-adsorbed aluminum-based fluorine adsorbent / desorbent, which is a solid content separated in step b,
Step d. A second solid-liquid separation step for solid-liquid separation of the desorbed liquid obtained in step c,

  And since the fluorine adsorption / desorption agent according to the present invention can be used repeatedly, it is preferable to add a step of repeatedly using the solid content (aluminum-based fluorine adsorption / desorption agent) recovered in step d to step a. It is. By adding this process, the aluminum-based fluorine adsorbent / desorbent that has been put into the process can be used repeatedly, and the desired effect can be achieved by simply replenishing the minimum amount of loss that has been discharged outside the system. It can be obtained continuously.

  Step a. The amount of aluminum-based fluorine adsorbent / desorbent added to the wet zinc smelting process liquid containing fluorine is preferably 100 to 300 times as the amount of aluminum with respect to the amount of fluorine in the wet zinc smelting process liquid. The addition amount of the aluminum-based fluorine adsorbent / desorbent is within a range that can be maintained at a fluorine concentration of 20 mg / l or less that does not cause a problem in actual operation, which has been obtained empirically. It is possible to further reduce the fluorine concentration. However, since excessive addition leads to loss of economic efficiency, it is preferable to make the addition amount that can be maintained at a fluorine concentration of 20 mg / l or less which does not cause a problem in actual operation.

  And said process a. In the process of adsorbing fluorine in the wet zinc smelting process liquid containing fluorine to the aluminum-based fluorine adsorbent / desorbent, the pH of the wet zinc smelting process liquid should be in the region of more than 3.0 and less than 7.0. Is preferred. This is the selectivity of OH · F of the ion exchange group possessed by the aluminum-based fluorine adsorbent / desorbent. When the pH is 7.0 or higher, the OH ion concentration in the liquid rises and ion exchange from OH to F is suppressed. Therefore, it is difficult to achieve a decrease in the fluorine concentration within the target concentration range. Further, when the pH is less than 3.0, the aluminum-based fluorine adsorbent / desorbent itself partially dissolves. Therefore, the pH of the wet zinc smelting process liquid is preferably in the range of more than 3.0 and less than 7.0. It is.

  Further, the above steps a. In the above, when the fluorine of the wet zinc smelting process liquid containing fluorine is adsorbed to the aluminum-based fluorine adsorbent / desorbent, the pH of the wet zinc smelting process liquid may be in the range of 4.0 or more and 6.0 or less. More preferred. This is also a more preferable range because the selectivity of the ion exchange group possessed by the aluminum-based fluorine adsorbent / desorbent increases further as the OH concentration decreases, as described above.

  And said process c. In this case, when desorbing fluorine from the aluminum-based fluorine adsorbing / desorbing agent adsorbing fluorine separated in step b, it is preferable that the pH of the desorption solution is in the region of 3.0 or less. By lowering the pH, a part of the aluminum-based fluorine adsorbent / desorbent itself is dissolved, and the adsorbed fluorine is released.

  Further, the above step c. It is more preferable that the pH of the desorption solution is 2.0 or more and 3.0 or less when desorbing fluorine from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. This pH range is a more preferable range because it is a pH range in which the dissolution of the aluminum-based fluorine adsorbent / desorbent itself is minimized and the adsorbed fluorine can be sufficiently released.

  In addition, the step c. In the above, it is also preferable to wash with water in a region where the pH exceeds 3.0 and is 5.0 or less before desorbing fluorine from the aluminum-based fluorine adsorbing / desorbing agent adsorbing fluorine separated in step b. The purpose of this step is to desorb other readily water-soluble elements or molecules that have been adsorbed simultaneously with fluorine in a pH range where adsorbed fluorine does not desorb.

  In addition, the step c. The pH of the desorption solution is preferably in the region of 7.0 or higher when desorbing fluorine from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. By raising the pH to this range, the OH ion concentration is increased and OH ions are substituted with fluorine to take the structure of the original aluminum-based fluorine adsorbent / desorbent, and the fluorine is ionized and eluted into the desorbed liquid. is there.

  Further, the above step c. It is more preferable that the pH of the desorption solution is 9.5 or more and 10.5 or less when fluorine is desorbed from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. This range of pH ≧ 9.5 is a preferable range in which ion exchange from F to OH occurs in the ion exchange group in which the OH concentration is increased and fluorine is adsorbed. Since pH> 10.5 is a region where the aluminum-based fluorine adsorbent / desorbent itself dissolves, it is more preferable that the pH of the desorption solution is 9.5 to 10.5. .

  And said process d. It is preferable to add a water-soluble alkaline earth metal compound to the desorbed liquid containing desorbed fluorine obtained in (1) to precipitate and separate fluorine as an alkaline earth metal compound. This process is carried out for the purpose of fixing and removing the desorbed fluorine ions as, for example, calcium fluoride and fixing the fluorine so that the fluorine does not enter the wet zinc smelting process liquid again. Since it is also a step of substituting fluorine in the desorption solution with OH, the desorption solution can be used repeatedly, which is preferable.

<Example>
The results of fluorine adsorption / desorption tests conducted with zinc leaching solution as the test solution are shown below. The zinc leaching solution is a solution obtained by dissolving crude zinc oxide obtained by regenerating zinc soot generated from steelmaking dust discharged in the steelmaking process with an electrolytic tail solution, and the component composition is shown in Table 1. As can be seen in Table 1, the fluorine concentration in the zinc leachate in the examples was 295 mg / l.

  The fluorine concentration in the zinc leachate was analyzed by the following measuring method. From the zinc leachate, 5 ml of the sample solution was collected in a 100 ml beaker, and 20 ml of 1 mol / l sodium citrate was added thereto and stirred. Thereafter, 40 ml of 0.5 mol / l EDTA · 2Na solution was added and stirred, and then adjusted to pH 8.0 using 10 wt% sodium hydroxide solution and / or 1.8 mol / l sulfuric acid. The total amount of the pH-adjusted solution was transferred to a 100 ml volumetric flask and made up with pure water to a volume of 100 ml. Then, 100 ml of this solution was transferred to a beaker, a fluorine ion electrode was inserted, and the potential was measured. Then, the fluorine concentration in the zinc leachate was calculated by collating with a calibration curve prepared in advance.

In this example, vialite (β-Al (OH) ₃ ) was used as a fluorine adsorbent / desorbent, and the experiment was repeated 5 cycles of adsorption and desorption in order to confirm the suitability of the fluorine adsorbent / recycler, All the results are shown in Tables 2 and 3.

<Fluorine adsorption>
Al / F value (the Al amount (mg) in the aluminum-based fluorine adsorbent / desorbent added to the amount of F (mg) in the zinc leachate) to 1 l of zinc leachate having a fluorine concentration of 295 mg / l is about 150. 46 g of bialite (β-Al (OH) ₃ ) was added as described above, and the mixture was heated and stirred at 60 ° C. and maintained at pH 4.5.After 2 hours, solid-liquid separation was performed, and the filtrate contained in the filtrate. The fluorine concentration was analyzed.

As can be seen from Table 2, the Al / F value was about 150, and as a result, the fluorine concentration in the zinc leachate was 11.3 mg / l to 18.1 mg / l (average of 14.30 mg / l). Was less than 20 mg / l. And the fluorine adsorption capacity of the viaite ((beta) -Al (OH) ₃ ) at this time is 6.25 mg-F / g-Al-6.41 mg-F / g-Al (average 6.34 mg-F / g-). Al).

<Fluorine desorption>
Next, the desorption treatment of fluorine from the aluminum-based fluorine adsorption / desorption agent that has adsorbed fluorine under the condition of Al / F value of 150 is for desorption adjusted to pH 10.0 to pH 10.5 using sodium hydroxide. An aluminum-based fluorine adsorbent / desorbent adsorbing fluorine in the solution was added to adjust the slurry concentration to 14 g-Al / l, and the mixture was stirred and maintained at 60 ° C. for 2 hours. Table 3 shows the desorption amount (mg) and desorption rate (%) of fluorine from the aluminum-based fluorine adsorbent / desorbent.

As is apparent from Table 3, the fluorine desorption rate from viaite (β-Al (OH) ₃ ), which is a fluorine adsorbent / desorbent treated with an Al / F value of about 150, is 92.0% to 97.3. % (Average 94.30%), which was a level that could be sufficiently used after regeneration.

  From the results shown in Tables 2 and 3, it is clear that there is almost no difference in the fluorine adsorption capacity of the aluminum-based fluorine adsorbent / desorbent that has been repeatedly used five times. Therefore, it became clear that the reused aluminum-based fluorine adsorbent / desorbent has the same adsorption ability as the aluminum-based fluorine adsorbent / desorbent used for the first time. In addition, the desorption rate (%) in the desorption treatment is stable regardless of the number of repetitions, and it is clear that the aluminum-based fluorine adsorbent / desorbent can be stably recycled. And the fluorine density | concentration 20 mg / l or less in the zinc leachate after the process which was the target also in the repeated use has been achieved.

  Although the contents of the present invention have been specifically shown in the above embodiments and examples, those skilled in the art can easily make various arrangements based on the basic idea and teaching of the present invention. In addition, there is no need to wait for the fact that there may be some variation in parameters and conditions when implemented on a pilot scale or mass production scale, and therefore the present invention is limited to the conditions of the above-described embodiments. is not.

  In the wet zinc smelting process, the fluorine concentration is controlled by removing fluorine from the process liquid for wet zinc smelting process obtained by dissolving the zinc-containing material containing a high level of fluorine before charging the zinc electrolysis process. Can be prevented from occurring. As a result, the zinc-containing material can be used as a zinc smelting raw material without hindering the operation of the wet zinc smelting process, and the cost of the wet zinc smelting process can be reduced.

Representative flow sheet of the process of removing fluorine from the process liquid for hydrometallurgical smelting containing fluorine according to the present invention

Claims (20)

An aluminum-based fluorine adsorbent / desorbent, which is a fluorine adsorbent / desorbent for adsorbing and removing fluorine from a wet zinc smelting process liquid containing fluorine, and is an aluminum compound. The aluminum-based fluorine adsorbent / desorbent is a basic aluminum sulfate-based aluminum compound (Al (SO ₄ ) _x (OH) _y (x and y are arbitrary real numbers)) and (AlO _a (OH) _b (SO ₄ ) The aluminum-based fluorine adsorbent / desorbent according to claim 1, wherein the aluminum-based fluorine adsorbent / desorbent is one or two selected from _c (H 2 O) _d (where a, b, c, and d are arbitrary real numbers). The aluminum-based fluorine adsorbent / desorbent according to claim 1, wherein the fluorine adsorbent / desorbent is aluminum oxyhydroxide (AlOOH). The aluminum-based fluorine adsorbent / desorbent according to claim 3, wherein the aluminum oxyhydroxide is boehmite (α-AlOOH) or diaspore (β-AlOOH). The aluminum-based fluorine adsorbent / desorbent according to claim 1, wherein the fluorine adsorbent / desorbent is aluminum hydroxide (Al (OH) ₃ ). The aluminum-based fluorine adsorbent / desorbent according to claim 5, wherein the aluminum hydroxide is gibbsite (α-Al (OH) ₃ ) or vialite (β-Al (OH) ₃ ). The aluminum-based fluorine adsorbent / desorbent according to claim 1, wherein the fluorine adsorbent / desorbent is aluminum oxide. The aluminum-based fluorine adsorbent / desorbent according to claim 7, wherein the aluminum oxide is alumina (Al ₂ O ₃ ). The pH region for adsorbing fluorine in the aluminum-based fluorine adsorbent / desorbent is an acidic region that exceeds pH 3.0 and less than pH 7.0, and the pH region that desorbs fluorine is pH 7.0 or more or pH 3.0 or less. The aluminum-based fluorine adsorbent / desorbent according to claim 1, wherein the aluminum-based fluorine adsorbent / desorbent is present. The aluminum-based fluorine according to any one of claims 1 to 9, which is a method for removing fluorine from a process liquid for wet zinc smelting containing fluorine, comprising the following steps a to d. Fluorine removal method using adsorption / desorption agent.
Step a. Fluorine adsorption step of adsorbing fluorine contained in the process liquid for wet zinc smelting to the aluminum-based fluorine adsorbent / desorbent step b. First solid-liquid separation step for solid-liquid separation of the treatment liquid obtained in step a Step c. Fluorine desorption step of desorbing fluorine from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine, which is the solid content separated in step b, step d. Second solid-liquid separation step for solid-liquid separation of the desorbed liquid obtained in step c   The aluminum-based fluorine adsorbent / desorbent according to claim 10, comprising the step of repeatedly using the aluminum-based fluorine adsorbent / desorbent, which is a solid content recovered in step d according to claim 10, in step a. Fluorine removal method using A process according to claim 10 a. The amount of aluminum-based fluorine adsorbent / desorbent added to the process solution for wet zinc smelting is 100 to 300 times as the amount of aluminum (unit: mg) relative to the amount of fluorine (unit: mg) in the process solution for wet zinc smelting The method for removing fluorine using the aluminum-based fluorine adsorbent / desorbent according to any one of claims 10 and 11, wherein A process according to claim 10 a. In the above, when the fluorine in the process solution for wet zinc smelting is adsorbed to the aluminum-based fluorine adsorbent / desorbent, the pH of the process solution for wet zinc smelting is in the region of more than 3.0 and less than 7.0. The fluorine removal method using the aluminum type fluorine adsorption / desorption agent in any one of Claims 10-12. A process according to claim 10 a. In the above, when the fluorine in the process liquid for wet zinc smelting is adsorbed to the aluminum-based fluorine adsorbent / desorbent, the pH of the process liquid for wet zinc smelting is in the range of 4.0 or more and 6.0 or less. The fluorine removal method using the aluminum-type fluorine adsorption / desorption agent of Claim 13. A process according to claim 10 c. The desorption solution has a pH of 3.0 or less when desorbing fluorine from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. The fluorine removal method using the aluminum type fluorine adsorption / desorption agent in any one of Claim 10 or Claim 11. A process according to claim 10 c. The pH of the desorption solution is 2.0 or more and 3.0 or less when fluorine is desorbed from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. The fluorine removal method using the aluminum type fluorine adsorption / desorption agent of Claim 15. A process according to claim 10 c. In the above, before desorbing fluorine from the aluminum-based fluorine adsorbing / desorbing agent adsorbing fluorine separated in step b, it is characterized in that it is washed with water in the region of more than 3.0 and not more than 5.0. A fluorine removal method using the aluminum-based fluorine adsorbent / desorbent according to any one of claims 15 and 16. A process according to claim 10 c. The desorption solution has a pH of 7.0 or more when desorbing fluorine from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. The fluorine removal method using the aluminum type fluorine adsorption / desorption agent in any one of Claim 10 or Claim 11. A process according to claim 10 c. The desorption solution has a pH of 9.5 or more and 10.5 or less when fluorine is desorbed from the aluminum-based fluorine adsorbent / desorbent adsorbing fluorine separated in step b. The fluorine removal method using the aluminum type fluorine adsorption / desorption agent of Claim 18. A process according to claim 10 d. The alkaline earth metal compound is added to the desorbed liquid containing desorbed fluorine obtained in the step 1, and fluorine is precipitated as an alkaline earth compound to be separated. A fluorine removal method using the aluminum-based fluorine adsorbent / desorbent according to claim 1.

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