JPS6383234A - Recovering method for nickel from nickel-containing iron material - Google Patents

Abstract

PURPOSE:To efficiently recover Ni from Ni-containing iron materials by simple operations without using large-sized equipments and with minimal energy, by using the oxidizing reaction of iron ions and the forming and precipitating reactions of iron hydroxide by pH regulation. CONSTITUTION:An Ni-containing iron powder is dissolved in an acid such as hydrochloric acid, etc., and then an oxidizing agent such as chlone is added to the resulting solution to oxidize iron ions from bivalence to trivalence. Subsequently, alkali such as caustic soda is added to the above solution to adjust pH to 3-6, so that precipirates of iron hydroxide are formed. Then the above precipitates are removed by a proper means such as filtration, and Ni is recovered by the well-known method, e.g., a method of recovering Ni from the resulting supernatant liquid in the form of metallic Ni by electrolysis.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for recovering nickel from a nickel-containing iron material, and more specifically, the nickel-containing iron material is mainly recovered from a ferric chloride aqueous solution. This is nickel-containing iron powder that is generated when nickel is removed using iron powder during recycling.

[Background of the invention]

When etching iron-nickel μ alloys such as amber materials and alloy materials using a ferric chloride aqueous solution, the iron-nickel μ
When nickel in the alloy material is eluted and becomes present in a large amount in the ferric chloride aqueous solution, the etching ability of the ferric chloride aqueous solution decreases and it becomes unusable. Therefore, it is necessary to purify and regenerate the ferric chloride aqueous solution.

As a method for purifying and regenerating such a ferric chloride aqueous solution,
A method of introducing iron material or iron powder into the ferric chloride aqueous solution has been proposed (Japanese Patent Application No. 84899/1982 and Japanese Patent Application No. 84400/1983).

At this time, iron powder containing nickel is obtained.

The present invention mainly focuses on the purification of such ferric chloride aqueous solution,
Although the present invention is directed to nickel-containing iron powder obtained from the regeneration process, it goes without saying that the present invention can also be applied to the production of nickel μ ore and nickel μ.

[Conventional technology]

Traditionally, the method of producing nickel from nickel-iron containing materials such as nickel ore has been to use siliconickel ore (N
i: about 2.8-8.5% by weight, Co: about 0.08-0.
05% by weight, Fe: about 7-15% by weight, MgO: about 25%
5102 (containing about 85-40 wt.%) at about 1000'C and gypsum 2 limestone in a blast furnace.

Coke is added and smelted to produce nickel crude (Ni+C).

: Approximately 20-25% by weight, Fc: Approximately 55-60% by weight, S
: 13 to 15% by weight), and charged this molten metal into a converter,
Furthermore, a method is provided for producing nickel by adding silica stone and blast-smelting it to oxidize and remove iron, then casting it into an anode, and performing electrolytic smelting using the thus obtained crude nickel anode. has been done.

[Problem that the invention seeks to solve]

However, the conventional methods described above require high temperatures and large amounts of electric power, and require large-scale equipment such as a blast furnace, a converter, and an electrolyzer. Therefore, in a relatively small-scale case where nickel μ is recovered from nickel-containing iron powder obtained from the purification and regeneration process of the ferric chloride aqueous solution, there is a problem in that the equipment and process costs are relatively high. ing.

[Failure to solve the problem]

As a means of solving the above-mentioned conventional drawbacks, the present invention provides a step of dissolving a nickel-containing iron phase in an acid, a step of adding an oxidizing agent to the solution prepared in step 1, a step of adding an oxidizing agent to the solution prepared in step 2, and an alkali solution to the solution obtained in step 2. to adjust the pH to 3.
- 6 Step 3 of forming a precipitate by using a sieve. Step 4 of removing the precipitate formed in the solution in step 3. Step 5 of recovering nickel from the supernatant liquid obtained in step 4.
The present invention provides a method for recovering nickel from nickel-containing iron material, which comprises steps 1, 2, 3, 4, and 5 above.

The nickel-containing iron material used in the present invention is mainly nickel-containing iron powder obtained from the purification and regeneration process of ferric chloride aqueous solution, but also nickel-containing iron powder obtained from ferric chloride aqueous solution.
As mentioned above, the target is kel-iron-containing substances. The Nikel-containing iron material can be in any shape, including not only powder but also scale, f#l shape, etc., but in order to efficiently perform acid dissolution in step 1, it must be in powder form with a large surface area. desirable. In the case of a powder, it is preferable from the viewpoint of safety that it contains water and is in the form of a slurry, but it is of course possible to use it even in a dry state. Furthermore, it may be advisable to separate the iron material containing Nimisakikeru with a magnet prior to step 1. In particular, the Nikel-containing iron material requires purification of ferric chloride aqueous solution,
In the case of the iron powder containing Urikel obtained from the regeneration process, it contains a large amount of iron hydroxide, and if the iron powder containing Ni-Kel contains a large amount of iron hydroxide, it will dissolve during the acid dissolution in Step 1. In order to prevent this, the iron powder containing Ni-Kel and the iron hydroxide are separated magnetically. The higher the nickel content in the Ni-Kel-containing iron powder, the better, but it is usually desirable for the Ni-Kel content to be 5% by weight or more. There is no problem even if the Ni-Kel-containing iron powder contains chromium or the like as a component other than iron and Ni-Kel. It is desirable that other impurities are not included as much as possible, but they may be present as long as they are insoluble in acids.

The present invention will be described in detail below in the order of the above steps.

In step 1, the iron material containing Nikel is dissolved in acid. The acid used for dissolution is mainly sulfuric acid.

Examples include inorganic acids such as hydrochloric acid. The dissolution reaction in step 1 using hydrochloric acid is shown below.

Fe + 2HC1-+Fe + 2C1+H2N1
+ 2HC#->N1+ 2CI2 +H2 The amount of the above acid used is 1.0 to 2.0 with respect to the amount required for the above reaction.
It is good to have about 1.0 to 1.5 times, preferably about 1.0 to 1.5 times. This is because if the amount of the acid used is less than 1.0 times the required amount, the Nikel-containing iron material will not dissolve sufficiently in the acid; This is because if the amount exceeds twice that, the amount of acid used becomes excessive for the purpose of sufficiently dissolving the iron material containing Ni.Kel. The higher the reaction temperature during the above reaction, the faster the reaction will proceed, but usually 4
A practically sufficient reaction rate can be obtained at about 0 to 90°C. Within this temperature range, the reaction is exothermic and there is no need to heat the reactor during the reaction. The above reaction temperature can be adjusted by adjusting the concentration of the acid used or the rate at which the nickel-containing iron material is added to the acid, etc., and there is no need to provide a heating means in the reactor unless the reactor is heated during the reaction, and There is no need to add heat energy from outside, so equipment costs and process costs are saved. The material of the reactor used in step 1 may be any material as long as it is resistant to acid, and if the temperature is within the above range, a reactor made of synthetic resin such as polyethylene or polyvinyl chloride, or a glass-coated reactor may be used. can be used. Further, the reactor may be provided with a stirring means such as a stirrer or an air blower in order to quickly dissolve the mixture. Furthermore, in step 1, safety considerations are necessary because hydrogen is generated by the above-mentioned dissolution reaction, and it is necessary to maintain the hydrogen concentration in the reactor below the explosion limit. For this purpose, it is desirable to use a reactor that is open to the atmosphere, or to apply a means of diluting the hydrogen concentration within the reactor by blowing air. The reaction time in step 1 is set to such an extent that most of the dioxins and iron are dissolved. Although it is better for the nickel and iron concentrations in the solution obtained after dissolving in this way to be high in order to efficiently generate sediment in step 8, if they are excessive, iron salts and di-ke/V salts Although precipitation may occur, the total concentration in terms of iron alone and 2.ke/v iron body is 2 from this point of view.
It is desirable that the amount be less than 0.00 gel and as close to 200 gal as possible. The amount of acid used above will of course affect the iron and nickel μ concentrations, and if the amount of acid used is excessive, the total concentration of iron and nickel will be significantly below 200 g/II. The solution obtained during the above-mentioned dissolution reaction may contain undissolved components, and in this case, the solution may be filtered, or the solution may proceed directly to step 2 without filtration. Since the solution contains iron in a sufficient and stable manner, the preferable pH is 2 or less, and furthermore, the pH is 1 or less.

In step 2, an oxidizing agent is added to the solution obtained in step 1 to change the iron ions in the solution from divalent to octavalent. The oxidizing agent used in step 2 is hydrogen peroxide, chlorine 9-hypochlorite.

Any known oxidizing agent such as air (oxygen) or ozone may be used. As a preferable example for step 2, a method using chlorine will be described below. The reaction apparatus shown in FIG. 1 includes a reaction vessel (1), a circulation path 0) communicating with the reaction vessel (1), a circulation pump (8) interposed in the circulation path (2), and an ejector. (4), and a stirrer (5) attached to the reaction vessel (1).
), and the ejector (4) has a chlorine supply path (6
) will contact you. J: In the reaction apparatus, a reaction vessel (1
), and the circulation pump (3) is operated to circulate the solution into the circulation path (2). The solution circulating through the circulation path (2) mixes and reacts with chlorine supplied from the chlorine supply path (6) in the ejector (4). In order for the reaction to proceed smoothly, the reaction temperature should be 40°.
C or higher, and if desired, a heating means may be added to the reaction apparatus in order to raise the reaction temperature to 40° C. or higher. The reason why the iron ions in the solution are changed from divalent to trivalent by the oxidation reaction in step 2 is to separate the octavalent iron ions thus obtained from the divalent iron hydroxide as iron hydroxide in step 8. From this point of view, the concentration of divalent iron ions remaining in the solution after step 2 is 0.5 g/l or less, more preferably 0.1 g/(! or less).

In step 8, an alkali is added to the solution containing divalent iron ions (Fe8+) and 29-μ ions (Nt 2+) obtained in step 2 to adjust the pH to 8 to 6. A more preferable pH at this time is 4 to 5.5. The alkali used in step 8 is caustic soda, caustic potash, soda carbonate, and potassium carbonate.

Although there are well-known alkalis such as inorganic alkalis such as lime and ammonia, and organic alkalis such as amines, it is preferable to use caustic soda or soda carbonate from the viewpoint of cost. In step 8, Fe8+ is precipitated as iron hydroxide. When the solution contains chromium, chromium hydroxide is also produced and precipitated.

Since the iron hydroxide precipitate may become colloidal, it is also recommended that a flocculant be added at the same time as or after the addition of the alkali to coagulate the precipitate and facilitate separation of the precipitate. As mentioned above, when the pH of the solution is raised to 8 or higher with an alkali, Fe8+ in the solution will precipitate as iron hydroxide, but in order to further facilitate the precipitation of the iron hydroxide, the pH is preferably 4 or higher. However, the pH of the solution is 6.
If the temperature exceeds 1,000 ml, hydroxide kneader/l/l will be produced, and the hydroxide kneader/l will co-precipitate with iron hydroxide, reducing the efficiency of iron hydroxide separation, so the pH of the solution should be 6 or less. The pH should be set at 5.0 to more reliably prevent the formation of hydroxide. F: It is desirable to do the following. Further, if the pH of the solution is less than 8, precipitation of iron hydroxide will not be completely formed. When using a strong alkali such as caustic soda, iron hydroxide may be included in the precipitate of iron hydroxide. The reason is not clear, but the part of the solution to which caustic soda was added temporarily has a Kp of 6 or more.
It becomes H, and hydroxides and kels are also produced together with iron hydroxide, and a mixed precipitate of iron hydroxide and nickel hydroxide is formed.Then, the pH of the solution becomes uniform and becomes 8 to 6 as a whole. It is presumed that because the redissolution rate of hydroxide is slow, 2.mu. remains in the mixed precipitate. When using a weak alkali such as soda carbonate, it is thought that the above-mentioned partial increase in the pH of the solution is unlikely to occur, and only iron hydroxide precipitates are formed, which is desirable. is more expensive than caustic soda, so it is recommended to use carbonated soda and caustic soda in combination. In other words, even if caustic soda is used until the pH of the solution reaches approximately 1 to 2, precipitation of iron hydroxide and hydroxide kel does not occur at all. It is desirable to adjust the pH of the solution to 8-6.

In step 4, the iron hydroxide precipitate thus produced is separated by known solid-liquid separation means such as filtration and sedimentation separation. As mentioned above, the precipitate may have a very small particle size and be in the form of a colloid. In this case, it is desirable to add a flocculant to the solution to make the precipitate coarser, but on the other hand, filtration When separating, in addition to using a flocculant or without using a flocculant, coarse filtration is performed using a filter cloth pre-coated with a filter aid such as diatomaceous earth to remove most of the precipitate. It is also desirable to perform fine filtration using a microfilter or the like after most of the precipitate has been removed by the precipitate separation. The supernatant liquid from which the precipitate has been separated contains a large amount of Ni-Kel and almost no iron. And the above steps 2, 8.4
If the iron content in the supernatant liquid is managed as specified, the iron content in the supernatant liquid can be
The following can be done.

In step 5, urikel is recovered from the supernatant obtained in step 4. The above Ni-K/L' recovery method includes (a) Ni-K sulfuric acid by concentration crystallization.

Well-known methods include a method of recovering it as a salt such as nickel chloride, (b) a method of adding an alkali to precipitate it into nickel hydroxide, and (c) a method of recovering it as a metal nickel by electrolysis.

[For production]

The present invention utilizes the oxidation reaction of iron ions, the production of iron hydroxide through pH adjustment, and the precipitation reaction in recovering Ni-Kel from iron materials containing Ni-Kel. That is, as mentioned above, the present invention dissolves iron and Ni-Kel by adding acid to the Ni-Kel-containing iron material (Step 1),
By adding an oxidizing agent to the obtained solution, divalent iron is oxidized to trivalent iron (Step 2), and an alkali is added to this solution to p
When the temperature is adjusted to 8 to 6, a precipitate of iron hydroxide is formed (step 8), the precipitate is then filtered (step 4), and 2.mu. is recovered from the remaining solution (step 5).

〔Effect of the invention〕

According to the method of the present invention, iron powder can be used to regenerate di-Kel-containing iron materials, especially ferric chloride aqueous solutions, without using large equipment such as blast furnaces or electrolytic refining equipment, and with generally little energy. Ni- produced when removing nickel
The present invention makes it possible to efficiently recover 2 to 2 Kels from Kel-containing iron materials through simple operations, making a great contribution to industry.

〔Example〕

2 kQ (2-K/L'1) of iron powder containing 2-Kel produced by denickeling using iron powder during refining and regeneration of ferric chloride.
1.8% by weight, 51.0% by weight of iron, residual moisture, etc.). After adding about 51 liters of water to this, 101 ml of hydrochloric acid (85%) was added little by little, and the mixture was reacted at a temperature of 60 to 70°C. After the generation of bubbles stopped, it was filtered, and after removing the reaction residue, the total amount was reduced to 701 tons. *. (7) Solution ke = -ke 18.1 g/L Iron 14.0 g/L)
Step 1). The solution obtained in step 1 above was charged into the apparatus shown in FIG. 1 and reacted with C12. Temperature 1d60~7
It was kept at 0°C. Completion of the reaction was confirmed by permanganate titration (Step 2). After adding 30% by weight NaOH to this solution to adjust the pH to 1, 2N-i acid sodium was added to adjust the pH to 5. A large amount of precipitate was generated (Step 3). The solution containing the precipitate was subjected to two-stage filtration using a filter using a filter cloth precoated with activated carbon and a cartridge-type microfilter to separate the precipitate. After separating the precipitate, water was added to the supernatant liquid to make a total volume of 1,401 ml. The concentration of Ni-ke A/concentration of the supernatant is 1.5
The iron concentration in g/l is 1. It was OF (Step 4). The following two methods are used to recover Nishizukuga μ from the supernatant liquid! ll
carried out.

(a) Using 701 of the supernatant, 30% by weight Na
The pH was adjusted to 8.5 with OH. The generated precipitate was collected by filtration. The recovered precipitate was 160g, 1/1
It contained 159.5% by weight. Therefore, the recovery rate from the first step was 84%.

(b) Use 51 of the supernatant liquid and add 80 g of boric acid to it.
/l, a carbon anode was used as an anode, a nickel plate was used as a cathode, and electrolysis was carried out at IA/dm for 1hr. The deposition efficiency of 21 ke μ is 93 based on the change in weight of the cathode after completion of stain analysis.
It was the lightest.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a reaction apparatus used in step 2. In the figure, (1)... Reaction vessel, (2)... Circulation path, (8)... Circulation pump, (4)... Ejector 1 (5)...・Agitator, (6)...Chlorine supply path

Claims (1)

[Claims] Step 1 of dissolving the nickel-containing iron material in acid; Step 2 of adding an oxidizing agent to the solution prepared in Step 1; Adding an alkali to the solution obtained in Step 2 to adjust the pH to 3.
Step 3 of generating a precipitate as ~6, and step 5 of recovering nickel from the supernatant liquid obtained in step 4, a step of removing the precipitate generated in the solution solution in step 3.
, A method for recovering nickel from a nickel-containing iron material, comprising steps 1, 2, 3, 4, and 5 above.