JP2003266065A - Removing method and recovering method for cobalt and/ or zinc in iron chloride solution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective method for reducing the amount of a consumed iron material and inhibiting increase in zinc concentration in an obtained ferrous chloride solution, in a method for recovering cobalt from a cobalt chloride- containing aqueous solution, such as etching waste water, and obtaining a ferrous chloride solution containing a low concentration of cobalt. <P>SOLUTION: The method for removing cobalt and/or zinc in the ferrous chloride solution comprises bringing the ferrous chloride solution containing cobalt and/or zinc into contact with an adsorbent to adsorb and remove the cobalt and/or zinc by the adsorbent. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to cobalt and / or
Alternatively, by adsorbing and separating cobalt and / or zinc from an iron chloride aqueous solution containing zinc by an adsorbent,
The present invention relates to a method for removing cobalt and / or zinc for the purpose of reducing the concentrations of these components in an aqueous iron chloride solution, and a method for recovering these components. It is suitable for the regeneration of the etching waste liquid after it is used for etching.

[0002]

2. Description of the Related Art An aqueous solution of ferric chloride is used as an inorganic coagulant and also as an etchant for etching various metals. Examples of the method for producing the ferric chloride aqueous solution include a method in which iron (scrap iron) is dissolved in hydrochloric acid to cause an oxidizing reaction such as blowing chlorine gas into the ferrous chloride aqueous solution obtained. At present, it is often obtained by recycling waste such as iron (scrap iron) is added to the pickling waste liquid of steel, and then chlorine is blown into the ferric chloride aqueous solution.

Another method for producing an aqueous solution of ferric chloride is the regeneration of waste liquid after etching various metals. Here, the waste liquid obtained when the iron-based alloy containing cobalt is etched with an aqueous solution of ferric chloride contains ferric chloride, ferrous chloride, cobalt chloride and the like.

[0004] Conventionally, as a method of regenerating the ferric chloride etching waste liquid containing nickel chloride generated by etching of a nickel-containing alloy, a method of using an iron material is generally used. That is, when these waste liquids and iron materials are reacted,
By the following reaction, a ferrous chloride aqueous solution is obtained together with the deposition of metallic nickel. 2FeCl ₃ + Fe → 3FeCl ₂ NiCl ₂ + Fe → Ni ↓ + FeCl ₂

In the regeneration of the ferric chloride etching waste liquid containing cobalt chloride, it is theoretically possible to deposit and separate metallic cobalt by the same method as the above-mentioned method for depositing and separating metallic nickel using an iron material. However, the removal limit concentration of cobalt in the treatment liquid by this method is higher than the removal limit concentration of nickel, and a considerable amount of iron material is required for removal, which causes a problem that the usage amount increases. Furthermore, the zinc component contained in the iron material added for the purpose of removing nickel and cobalt is dissolved in the treatment liquid,
There is also a problem that the concentration of impure metals in the regenerated ferric chloride solution increases.

[0006]

The object of the present invention is to collect cobalt from an aqueous solution containing cobalt chloride such as an etching waste liquid and to obtain an aqueous solution of ferrous chloride having a low cobalt concentration. An object of the present invention is to provide an effective method for reducing the amount and suppressing an increase in zinc concentration in the obtained ferrous chloride aqueous solution.

[0007]

Means for Solving the Problems As a result of intensive studies by the present inventors in order to solve the above problems, as a result of contacting an aqueous solution of ferrous chloride containing cobalt and / or zinc with an adsorbent, the adsorption The present invention has been completed by discovering that cobalt and / or zinc can be efficiently adsorbed and separated in the agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Cobalt and / or
Or an aqueous ferrous chloride solution containing zinc is an iron-based alloy containing cobalt, for example, Ultra Invar material, by adding iron to the etching waste liquid after etching with an aqueous ferric chloride solution to remove residual ferric chloride. Examples include those reduced to ferrous chloride. In this case, when other metal such as nickel is contained in the alloy, it is often performed to deposit and separate the metal on the surface of the reducing iron or the iron added separately. In this case, depending on the type of iron used, zinc contained therein will be eluted in the iron chloride aqueous solution.

Since the ferrous chloride aqueous solution contains a large amount of ferrous chloride ions and a small amount of cobalt and / or zinc ions, adsorption of cobalt and / or zinc ions on the adsorbent is inhibited by iron ions. To be done. In order to reduce this inhibition, it is preferable to dilute the ferrous chloride aqueous solution with water. The amount of water added is an advantage that the amount of the treatment liquid and the amount of the adsorbent used can be small if the amount is too small, but adsorption inhibition by the ferrous ion increases, while if the amount added is too large, the treatment liquid The amount of money increases and it becomes uneconomical. Specifically, the ferrous ion content in the ferrous chloride aqueous solution is 5 to 30.
%, Preferably about 5 to 15%.

Examples of the adsorbent used in the present invention include chelate resins and ion exchange resins. Chelate resins are preferred because of their good selective adsorption of cobalt and / or zinc. Although there are various kinds of chelate resins, a (N, N) -based chelate resin in which a combination of functional groups involved in chelate bonding is nitrogen atoms is particularly preferable, because adsorption of cobalt and / or zinc is particularly good. When adsorbing cobalt and / or zinc by the chelate resin, the pH of the ferrous chloride aqueous solution is in the range of 2 to 4,
This is preferable because the adsorption capacity is increased.

With respect to the amount of the ferrous chloride aqueous solution to be treated, the higher the admixture ratio is, the better the removal efficiency of cobalt and / or zinc is, but the adsorbent is expensive and the equipment cost is high. Therefore, the ratio between the adsorbent and the liquid amount (SV ratio) may be determined in consideration of economic efficiency. If the temperature at the time of adsorption is too high, ferrous chloride in the liquid is likely to be air-oxidized to ferric iron, and this ferric chloride has extremely great inhibition of adsorption on cobalt and / or zinc. Therefore, it is preferable to perform the adsorption at around room temperature. The longer the adsorption time, the more preferable, but it should be appropriately selected from the viewpoint of economy.

When the contact with the adsorbent is carried out in the presence of an oxidizing agent such as oxygen, ferric chloride is easily generated in the liquid as described above. Therefore, it is preferably performed in a non-oxidizing atmosphere. Specifically, in the case of batch processing, a method of blowing nitrogen gas from under the reaction tank to replace oxygen in the liquid and in the vicinity of the liquid surface can be mentioned, and in the case of continuous processing, a method of making the system a nitrogen atmosphere, etc. Is mentioned.

If the adsorbent that has adsorbed cobalt and / or zinc is washed with a desorbent such as hydrochloric acid, the metal is desorbed and the adsorbent can be reused. On the other hand, when a metal having a higher ionization tendency than cobalt and / or zinc, such as manganese, chromium, vanadium, or titanium, is added to the desorbed liquid after washing, metal cobalt and / or zinc is deposited on the surface thereof. By separating and recovering this, these metals can be reused.

The method for removing cobalt and / or zinc from an aqueous solution of iron chloride according to the present invention is combined with a conventional method of adding a ferrous material to an aqueous solution of ferric chloride containing cobalt chloride to deposit and separate metallic cobalt. Can be used. This makes it possible to perform the adsorption and separation operation of cobalt and / or zinc after sufficiently separating and removing nickel, which causes adsorption competition with cobalt for the resin, by the conventional method, and the resin regeneration cost due to the extension of the adsorption life of the resin. Can be reduced. Further, it is possible to suppress an increase in zinc concentration in the obtained ferrous chloride aqueous solution.

[0015]

When the method of the present invention is used, cobalt ions originally contained in the etching waste liquid, zinc ions eluted from the iron material when the metal such as nickel is deposited and removed by adding the iron material to the etching waste liquid, etc. It can be removed efficiently. The reason for this is that ferric chloride in the liquid is reduced to ferrous chloride, so there is almost no ferric chloride that prevents adsorption of cobalt and / or zinc to the adsorbent. it is conceivable that. There is also a method in which the etching waste liquid itself is brought into contact with the adsorbent, but since the adsorbent has a characteristic that ions having a higher valence are more likely to be adsorbed, ferric ion is adsorbed first. For this reason,
It means that cobalt ions and the like having a small content can hardly be adsorbed.

[0016]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. (Example 1) A ferrous chloride aqueous solution (35.7%, pH 3) at room temperature containing 341 ppm of cobalt and a (N, N) -based chelating resin as an adsorbent in a beaker at a volume ratio of 2.5: 1. After being charged and stirred for 20 minutes, the treatment liquid and the chelate resin are separated, and the cobalt concentration in the treatment liquid is 209
It was confirmed that it was reduced to ppm. At this time, the ferrous chloride concentration in the treatment liquid was 32.4%.

(Example 2) A ferrous chloride aqueous solution at room temperature containing 323 ppm of cobalt and 57 ppm of zinc (36
%, PH 3) was diluted with pure water to a cobalt concentration of 80 ppm, a zinc concentration of 14 ppm, and a ferrous chloride concentration of 8.9%, and a treated stock solution was filled with an (N, N) -based chelate resin as an adsorbent for continuous flow. The mold treatment vessel was passed under a nitrogen atmosphere at a flow rate of 2.5 times the volume of the filled resin per hour, and the cobalt concentration and zinc concentration in the treatment solution flowing out of the treatment vessel were measured. The results are shown in FIG. 1, and it was confirmed that the concentrations of both cobalt and zinc can be significantly reduced as compared with the undiluted solution. Further, it is understood that the chelating resin has a limited adsorption capacity, the cobalt concentration in the liquid that has passed through gradually increases, and regeneration is necessary when the cobalt concentration exceeds a certain level.

(Comparative Example 1) A ferrous chloride aqueous solution (35%) containing 740 ppm of cobalt and a large excess amount of iron powder were charged into a beaker, and the mixture was stirred at a temperature of 80 ° C for 6 hours and stirred every 1 hour. The cobalt concentration in the reaction solution was measured. As a result, the cobalt concentration was 330 pp even after 6 hours.
It decreased only to m.

(Comparative Example 2) The reaction liquid after the reaction for 6 hours in Comparative Example 1 was separated from the residual iron powder, and again reacted with the same type of new iron powder in the same manner as in Comparative Example 1. As a result, the reduction rate of the cobalt concentration after 6 hours was 10%.

(Embodiment 3) In the same manner as in Embodiment 2, the stock solution for treatment was continuously passed through the chelate resin-filled container without diluting with pure water. As shown in FIG. It was confirmed that the rate of decrease in concentration was lower than that in the case where no dilution was performed, and the cumulative amount of liquid that could be adsorbed and removed also decreased.

[0021]

According to the present invention, an aqueous ferrous chloride solution containing cobalt and / or zinc is allowed to flow through a layer filled with an adsorbent such as a chelate resin without being diluted with water. The cobalt and / or zinc contained in the ferrous chloride solution can be efficiently adsorbed and separated by a simple method.

[Brief description of drawings]

FIG. 1 is a graph of cobalt / zinc concentration-time of Example 2.

FIG. 2 is a graph of cobalt concentration-time in Example 3.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01J 20/34 B01J 20/34 G C02F 1/62 C02F 1/62 Z 1/70 1/70 A C22B 3 / 42 C22B 19/22 3/46 23/04 19/00 3/00 M 23/00 U (72) Inventor Akihiro Sakata 23, Toagosei Co., Ltd. 23, 17 Showa-cho, Minato-ku, Nagoya-shi, Aichi F-term (reference) 4D024 AA04 AB17 BA17 BA18 DA08 4D038 AA08 AB67 AB69 AB78 AB88 BB06 4D050 AA13 AB56 AB58 BA01 CA06 CA20 4G066 AE10B CA46 DA08 GA11 4K001 AA07 AA30 BA19 BA21 DB18 DB36 DB36

Claims (6)

[Claims] 1. A ferrous chloride aqueous solution containing cobalt and / or zinc is brought into contact with an adsorbent,
A method for removing cobalt and / or zinc in an aqueous solution of iron chloride, which comprises adsorbing and separating cobalt and / or zinc on the adsorbent. 2. The ferrous chloride aqueous solution containing cobalt and / or zinc is diluted with water and then contacted with the adsorbent, and the cobalt and / or the ferric chloride aqueous solution according to claim 1 is contacted. How to remove zinc. 3. The method for removing cobalt and / or zinc from an aqueous solution of iron chloride according to claim 1 or 2, wherein the contact with the adsorbent is performed in a non-oxidizing atmosphere. 4. A ferrous chloride aqueous solution containing cobalt and / or zinc is obtained after metallic iron is added to an etching waste liquid containing other metals to precipitate and separate other metals from iron. It is the one that has been obtained.
4. The method for removing cobalt and / or zinc from an aqueous solution of iron chloride according to any one of 3 to 3. 5. The cobalt and / or zinc in the aqueous solution of iron chloride according to claim 1, wherein the adsorbent adsorbing cobalt and / or zinc is regenerated by a desorption solution, and then the adsorbent is reused. / Or a method of removing zinc. 6. A ferrous chloride aqueous solution containing cobalt and / or zinc is brought into contact with an adsorbent,
After adsorbing and separating cobalt and / or zinc on the adsorbent, the adsorbent is washed with a desorption solution, and a metal having a greater ionization tendency than cobalt and / or zinc is added to the desorption solution to remove the metal. A method for recovering cobalt and / or zinc in an aqueous solution of iron chloride, which comprises depositing metal cobalt and / or metal zinc on the surface of, and separating and recovering.