KR102384295B1 - Apparatus And Method For Recovering Nickel Or Nickel Compound - Google Patents

Abstract

The present invention provides a method for selectively recovering nickel or nickel compounds from nickel raw materials. One aspect according to an embodiment of the present invention includes a dissolution unit for forming a nickel solution by dissolving a nickel raw material in a solvent; a filtering unit for filtering foreign materials in the nickel solution; an electrowinning unit that includes a positive electrode tank including a positive electrode, a negative electrode tank including a negative electrode, and a positive ion exchange diaphragm partitioning the positive electrode tank and the negative electrode tank and extracts nickel or nickel compounds from the negative electrode tank through electrowinning; and a recovery unit for recovering the nickel or nickel compounds extracted from the negative electrode tank of the electrowinning unit.

Description

Nickel metal or nickel compound recovery apparatus and method {Apparatus And Method For Recovering Nickel Or Nickel Compound}

The present invention relates to a nickel metal or nickel compound recovery apparatus and method.

Nickel is one of the six major non-ferrous resources and is a useful element widely used in various industrial fields such as secondary batteries, electronic parts, and special steels. In particular, nickel metal is used for stainless steel, nickel sulfate is used for nickel plating, and nickel hydroxide is used as a cathode material for nickel-cadmium batteries or nickel-hydrogen alloy batteries. Not only nickel metal but also nickel compounds are used for various purposes. it can be confirmed that

However, since such nickel is expensive and most of it is imported, nickel is obtained from low-price, low-purity minerals such as southern resources, nickel waste, nickel scrap, and nickel by-products such as nickel MHP and nickel MSP, which are by-products of nickel oxide ore smelting. The need for an apparatus and method capable of recovering is emerging.

In Korean Patent Publication No. 2007-7020915, the HPAL process is disclosed. HPAL (High Pressure Acid Leaching) process is a method to recover nickel by acid dissolving nickel-containing metals such as limonite and saprolite in an autoclave under high temperature and high pressure. It has excellent performance.

However, the HPAL method has a disadvantage in that it has to be performed at high temperature and high pressure, and since it uses a strong acid solution, it is necessary to use a titanium material mainly, so that the equipment and operation are expensive. In addition, the HPAL method is environmentally harmful because sludge, which is 100 times the amount of nickel production, is produced as a by-product.

Meanwhile, Korean Patent No. 1214187 discloses an alkali addition precipitation method. The alkali addition precipitation method is a method of recovering nickel by precipitating it as nickel hydroxide by adding an alkali such as caustic soda to the electroless plating waste solution. This is a useful process when recovering nickel hydroxide.

However, since the alkali addition precipitation method requires a very strong alkali solution of pH 14 or higher, an excess of a pH adjusting agent such as caustic soda is used, and various organic substances such as phosphorus may be mixed as impurities.

Meanwhile, Korean Patent Publication No. 1659707 and Korean Patent Publication No. 1799500 disclose another useful method for extracting metals, electrolytic extraction. Electrolytic extraction is a method of dissolving metal to make an electrolyte, installing anode and anode in the electrolyte, and applying electric current to the cathode and anode to extract metal from the cathode. way.

However, since this electrolytic extraction is a method of extracting metals, if nickel is recovered through electrolytic extraction, nickel metal can be recovered, but compounds such as nickel hydroxide and nickel carbonate cannot be recovered, and nickel hydroxide and nickel carbonate cannot be recovered. There is a disadvantage that an additional process using nickel metal is required for recovery.

Republic of Korea Patent Publication No. 2007-7020915 (Title: Improved acid leaching method of laterite ore) Republic of Korea Patent Publication No. 1214187 (Name: treatment method of electroless nickel plating wastewater) Republic of Korea Patent Publication No. 1659707 (Name: Copper recovery device using copper-containing waste liquid and copper recovery method accordingly) Republic of Korea Patent Publication No. 1799500 (Name: Manufacturing method of copper sulfate using copper chloride waste solution)

It is an object of the present invention to show an apparatus and method for recovering nickel metal or nickel compound.

One aspect of the nickel metal or nickel compound recovery apparatus according to an embodiment of the present invention for achieving the above object is a dissolving unit 100 in which a nickel raw material is dissolved in a solvent to form a nickel solution; a filtration unit 200 for filtering impurities in the nickel solution; An anode tank 310, which receives the nickel solution from which impurities have been filtered, and is provided with an anode 311, a cathode tank 320 and a cathode tank 320 and anode tank 310 and a cathode tank ( and a cation exchange membrane 330 that partitions 320), and when power is applied to the positive electrode 311 and the negative electrode 321, the nickel metal or nickel compound is selectively extracted from the negative electrode tank 320 ( 300); and a recovery unit 400 for recovering the extracted nickel metal or nickel compound.

In one aspect of the embodiment of the present invention, in the negative electrode tank 320, nickel metal or nickel compound is selectively extracted according to the pH of the injected electrolyte.

In one aspect of the embodiment of the present invention, it further includes a pH adjusting unit 500 for adjusting the pH of the electrolyte injected into the negative electrode tank (320).

In one aspect of the embodiment of the present invention, the pH adjusting unit 500 injects a pH adjusting agent into the negative electrode tank 320 to adjust the pH of the electrolyte injected into the negative electrode tank 320 .

In one aspect of the embodiment of the present invention, the pH adjusting unit 500 adjusts the voltage applied to the positive electrode 311 and the negative electrode 321 in order to adjust the pH of the electrolyte injected into the negative electrode tank 320 . .

In one aspect of the method for recovering nickel metal or nickel compound using the nickel metal or nickel compound recovery apparatus according to an embodiment of the present invention, the dissolving unit 100 dissolves the nickel raw material in a solvent to form a nickel solution a dissolution step (S100); a filtration step (S200) in which the filtering unit 200 filters impurities in the nickel solution; In the extraction unit 300, cations are exchanged through a cation exchange diaphragm 330 between the nickel solution in which the impurities introduced into the anode tank 310 are filtered and the electrolyte input into the cathode tank 320, and the cathode tank ( Extracting the nickel metal or nickel compound in 320) (S300); and a recovery step (S500) in which the recovery unit 400 recovers the extracted nickel metal or nickel compound.

In one aspect of the embodiment of the present invention, the pH adjusting unit 500 further includes a pH adjusting step (S400) of adjusting the pH of the electrolyte injected into the negative electrode tank 320, and in the extraction step (S300), the Nickel metal or nickel compound is extracted according to the pH of the electrolyte added to the negative electrode tank 320 adjusted in the pH adjustment step (S400).

In one aspect of the embodiment of the present invention, in the pH adjusting step (S400), the pH adjusting unit 500 inputs a pH adjusting agent to the negative electrode tank 320 .

In one aspect of the embodiment of the present invention, in the pH adjusting step (S400), the anode 311 and the cathode 321 in which the pH adjusting unit 500 is provided in the anode tank 310 and the cathode tank 320, respectively. ) to adjust the voltage applied to the

In one aspect of the embodiment of the present invention, in the pH adjusting step (S400), when the pH adjusting unit 500 adjusts the pH of the electrolyte injected into the negative electrode tank 320 to 2.0 or less, the extraction step (S300) ), nickel metal is extracted from the cathode tank 320 .

In one aspect of the embodiment of the present invention, in the pH adjusting step (S400), when the pH adjusting unit 500 adjusts the pH of the electrolyte injected into the negative electrode tank 320 to 2.5 to 5.5, the extraction step ( In S300), nickel metal and nickel oxide are extracted from the cathode tank 320.

In one aspect of the embodiment of the present invention, in the pH adjusting step (S400), the pH adjusting unit 500 adjusts the pH of the electrolyte injected into the negative electrode tank 320 to 5.0 to 5.5, and the negative electrode tank ( When sodium carbonate is added to 320), nickel carbonate is extracted from the negative electrode tank 320 in the extraction step (S300).

In one aspect of the embodiment of the present invention, in the pH adjusting step (S400), when the pH adjusting unit 500 adjusts the pH of the electrolyte injected into the negative electrode tank 320 to 7.0 or higher, the extraction step (S300) ), nickel hydroxide is extracted from the cathode tank 320 .

According to the selective recovery apparatus and method of nickel metal or nickel compound using a nickel raw material according to an embodiment of the present invention, the following effects can be expected.

First, in the present invention, nickel metal or nickel compound can be selectively electrolytically collected through pH adjustment. Therefore, according to the embodiment of the present invention, it is possible to widen the range of choices in the nickel recovery process.

1 is a block diagram of a nickel metal or nickel compound recovery device according to an embodiment of the present invention.
Figure 2 is a flowchart of a nickel metal or nickel compound recovery method according to an embodiment of the present invention.
3 is a schematic diagram of a process in which nickel metal is extracted in an embodiment of the present invention.
Figure 4 is a photograph of the nickel metal recovered in the embodiment of the present invention.
5 is a schematic diagram of a process in which nickel oxide is extracted in an embodiment of the present invention.
6 is a photograph of nickel oxide recovered in an embodiment of the present invention.
7 is a schematic diagram of a process in which nickel carbonate is extracted in an embodiment of the present invention.
8 is a photograph of nickel carbonate recovered in an embodiment of the present invention.
9 is a schematic diagram of a process in which nickel hydroxide is extracted in an embodiment of the present invention.
10 is a photograph of nickel hydroxide recovered in an embodiment of the present invention.

Hereinafter, a nickel metal or nickel compound recovery apparatus according to an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a block diagram showing a nickel metal or nickel compound recovery apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the recovery device according to an embodiment of the present invention selectively recovers nickel metal or nickel compound. The recovery device includes a dissolving unit 100 , a filtering unit 200 , an extraction unit 300 , a recovery unit 400 , and a pH adjusting unit 500 .

More specifically, in the dissolving unit 100, a nickel raw material is dissolved in a solvent to form a nickel solution. As the nickel raw material used in the dissolving unit 100, nickel scrap, nickel MHP, nickel MSP, nickel carbonate, which are by-products of smelting nickel oxide ore, may be used. And as the solvent used in the dissolving unit 100, an acid solution such as sulfuric acid or hydrochloric acid may be used, and water may be used for a nickel raw material that is well soluble in water such as nickel sulfate.

The filtering unit 200 is a place for filtering impurities in the nickel solution formed in the dissolving unit 100 , and may include a filter 210 and an ion exchange resin 220 . More specifically, the filter 210 may filter insoluble impurities not dissolved in the dissolving unit 100 . In addition, the ion exchange resin 220 may filter impurities dissolved in the nickel solution. As such, the purity of the nickel metal or nickel compound extracted from the nickel raw material may be ultimately increased by the filtration of impurities by the filter 210 and the ion exchange resin 220 .

Next, the extraction unit 300 extracts a nickel metal or a nickel compound from the nickel solution in which impurities have been filtered through the filtering unit 200 . In an embodiment of the present invention, the extraction unit 300 includes an anode tank 310 , a cathode tank 320 , and a cation exchange diaphragm 330 .

The anode tank 310 receives the nickel solution, and an anode 311 is provided therein. Practically, the nickel solution injected into the anode tank 310 circulates between the dissolving unit 100 and the anode tank 310 .

In addition, the cathode tank 320 receives an electrolyte solution, and a cathode 321 is provided therein. The electrolyte injected into the cathode tank 320 circulates between the recovery unit 400 and the cathode tank 320 as will be described later.

The cation exchange diaphragm 330 is a diaphragm that can transmit cations but not anions, and in the present invention, mainly nickel cations (Ni ²⁺ ) and hydrogen ions (H ⁺ ) permeate. The cation exchange membrane 330 partitions the anode tank 310 and the cathode tank 320 . Accordingly, when power is applied to the positive electrode 311 and the negative electrode 321 , hydrogen ions (H ⁺ ) are generated in the positive electrode 311 , and hydroxide ions (OH ⁻ ) are generated in the negative electrode 321 . In addition, the nickel metal and the nickel compound may be extracted from the negative electrode tank 320 . In the extraction process, some nickel metal and nickel compound may be attached to the negative electrode 321, and may be recovered later. A more detailed process in which the nickel metal and nickel compound are extracted will be described in detail through experimental examples in the Examples of the present invention.

Next, in the recovery unit 400 , some nickel metals and nickel compounds extracted from the negative electrode tank 320 may be recovered. The recovery method may include filtration through a filter. The electrolyte from which nickel metal has been recovered after being filtered by the recovery unit 400 is again introduced into the negative electrode tank 320 and circulated between the recovery unit 400 and the negative electrode bath 320 . In the present embodiment, the recovery unit 400 includes a first recovery unit and a second recovery unit 420 . The first recovery unit is a place where nickel metal is recovered, and the second recovery unit 420 is a place where a nickel compound is recovered. In this embodiment, since the nickel metal is recovered from the negative electrode 321 , the first recovery unit may be understood as substantially the negative electrode 321 .

Next, the pH adjusting unit 500 adjusts the pH of the electrolyte in the negative electrode bath 320 so that the nickel metal and the nickel compound are selectively extracted from the negative electrode bath 320 . More specifically, the pH adjusting unit 500 may adjust the pH by adding a pH adjusting agent to the negative electrode tank 320 . In addition, the pH adjusting unit 500 controls the voltage applied to the positive electrode 311 and the negative electrode 321 to generate hydrogen ions (H ⁺ ) generated in the positive electrode 311 and generated in the negative electrode 321 . You can adjust the pH by adjusting the amount of hydroxide ions (OH ^- ).

As the pH adjusting agent, sulfuric acid, hydrochloric acid, etc. may be used as a pH adjusting agent for lowering the pH, and sodium hydroxide, potassium hydroxide and sodium carbonate may be used as a pH adjusting agent for increasing the pH.

The voltage may be adjusted to 4.0V to 6.0V.

As the pH adjusting unit 500 adjusts the composition and pH of the electrolyte in the negative electrode tank 320 , the nickel metal and nickel compound may be selectively recovered.

2 is a flowchart of a nickel metal or nickel compound recovery method according to an embodiment of the present invention.

2, in the recovery method according to an embodiment of the present invention, nickel metal or nickel compound is selectively recovered. The recovery method includes a dissolution step (S100), a filtration step (S200), a pH adjustment step (S300), an extraction step (S400), and a recovery step (S500).

More specifically, in the dissolving step (S100), the dissolving unit 100 dissolves the nickel raw material in a solvent to form a nickel solution.

The types of the nickel raw material and the nickel solution used in the dissolution step (S100) are the same as those used in the dissolution unit (100).

In the filtering step (S200), the filtering unit 200 filters impurities in the nickel solution.

The filtration step (S200) may include a filter filtration step (S210) in which the filter 210 is used and an ion exchange resin filtration step (S220) in which the ion exchange resin 220 is used, and the filter ( 210) and the roles of the ion exchange resin 220 are as described above.

In the pH adjusting step (S300), the pH adjusting unit 500 adjusts the pH of the electrolyte in the negative electrode tank 320 .

More specifically, in the pH adjusting step (S300), as described above, the pH adjusting unit 500 inputs a pH adjusting agent such as sulfuric acid, hydrochloric acid, sodium hydroxide, potassium hydroxide and sodium carbonate to the negative electrode tank 320 . It is possible to adjust the pH of the electrolyte in the cathode tank 320 . In addition, the pH control unit 500 adjusts the voltage applied to the positive electrode 311 and the negative electrode 321 , the amount of hydrogen ions (H ⁺ ) generated in the positive electrode 311 and the hydroxylation in the negative electrode 321 . The amount of ions (OH ^- ) generated can be controlled. Finally, through the voltage control, the pH of the electrolyte in the negative electrode tank 320 may be adjusted.

In the extraction step (S400), the extraction unit 300 extracts nickel metal or nickel compound from the nickel solution.

More specifically, the nickel metal and the nickel compound are selectively recovered according to the pH of the electrolyte in the negative electrode tank 320 adjusted in the pH adjustment step (S300).

In the recovery step (S500), some of the nickel metal and nickel compound attached to the negative electrode 321 are recovered. In addition, some of the nickel metal and nickel compound extracted from the recovery unit 400 are filtered, washed with water, dried, and recovered.

Hereinafter, the present invention will be described in more detail by way of Examples and Experimental Examples. These Examples and Experimental Examples are merely for illustrating the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited to these Examples and Experimental Examples.

Example

In an embodiment of the present invention, the nickel raw material and the solvent were mixed in the dissolution step (S100) to form a nickel solution. Nickel metal was used as the nickel raw material, and 20 wt% sulfuric acid solution was used as the solvent. The nickel metal was dissolved in the sulfuric acid solution at a concentration of 15 g/L to form the nickel solution.

In the filtering step (S200), the filter 210 was used to filter impurities in the nickel solution, and then, it was introduced into the anode tank 310 .

In the pH adjustment step (S300), an electrolyte having a specific pH was prepared. The pH of the pH adjusting agent and the electrolyte used in the pH adjusting step (S300) are shown in Table 1 below. The electrolyte was introduced into the cathode tank 320 .

In the extraction step (S400), a voltage of 5V was applied to the anode 311 and the cathode 321, and electrolysis was collected for 24 hours. Since the pH was changed during the electrolytic sampling process, the pH was frequently readjusted to maintain the pH.

In the recovery step (S500), some nickel metals and nickel compounds attached to the negative electrode 321 are recovered, and some nickel metals and nickel compounds that have settled in the negative electrode tank 320 are filtered and recovered.

electrolyte pH adjuster pH Preparation Example 1 sulfuric acid 0.9 Preparation 2 sulfuric acid 1.0 Preparation 3 sulfuric acid 1.2 Preparation 4 sulfuric acid 1.3 Preparation 5 sulfuric acid 1.4 Preparation 6 sulfuric acid 1.5 Preparation 7 sulfuric acid 1.6 Preparation 8 sulfuric acid 1.7 Preparation 9 sulfuric acid 1.8 Preparation 10 sulfuric acid 1.9 Preparation 11 sulfuric acid 2.0 Preparation 12 sulfuric acid 2.5 Preparation 13 sulfuric acid 3.0 Preparation 14 sulfuric acid 3.5 Preparation 15 sulfuric acid 4.0 Preparation 16 sulfuric acid 4.5 Preparation 17 sulfuric acid 5.0 Preparation 18 sulfuric acid 5.5 Preparation 19 sulfuric acid and sodium carbonate 5.0 Preparation 20 sulfuric acid and sodium carbonate 5.5 Preparation 21 sulfuric acid 6 Preparation 22 sulfuric acid 6.5 Preparation 23 sulfuric acid 7 Preparation 24 sulfuric acid 7.5 Preparation 25 sulfuric acid 8 Preparation 26 sulfuric acid 8.5 Preparation 27 sulfuric acid 9 Preparation 28 sulfuric acid 9.5 Preparation 29 sulfuric acid 10.5 Preparation 30 sulfuric acid 11.0

<Experimental Example 1>

Table 2 shows the results of inductively coupled plasma analysis of the nickel metal and nickel compound recovered in <Preparation Examples 1 to 11>.

3 is a schematic diagram of a process in which nickel metal is extracted in <Experimental Example 1>.

4 is a photograph of the nickel metal recovered in <Preparation Example 1>.

pH of the electrolyte Total Yield (%) Nickel metal ratio (%) Nickel oxide percentage (%) Preparation Example 1 0.9 100.0 100.0 0.0 Preparation 2 1.0 100.0 100.0 0.0 Preparation 3 1.2 100.0 100.0 0.0 Preparation 4 1.3 100.0 100.0 0.0 Preparation 5 1.4 100.0 100.0 0.0 Preparation 6 1.5 100.0 100.0 0.0 Preparation 7 1.6 100.0 100.0 0.0 Preparation 8 1.7 100.0 100.0 0.0 Preparation 9 1.8 100.0 100.0 0.0 Preparation 10 1.9 100.0 99.9 0.1 Preparation 11 2.0 99.5 99.5 0.5

In <Experimental Example 1>, electrolytic sampling was performed in an electrolyte solution having a pH of 2 or less. Referring to Table 2, it can be seen that when the pH of the electrolyte is 2.0 or less, nickel metal is mainly recovered from the electrolyte.

The process of recovering the nickel metal will be described in more detail with reference to FIG. 3 and Chemical Formula 1 below. Nickel ions (Ni ²⁺ ) dissolved in the nickel solution pass through the cation exchange membrane 330 due to the electromotive force of the negative electrode 321 and move to the negative electrode tank 320 . The nickel ions (Ni ²⁺ ) move to the negative electrode 321 , meet electrons at the negative electrode 321 , and are recovered as nickel metal through Chemical Formula 1 below.

<Formula 1>

Ni ²⁺ + 2e ^- → Ni

The nickel metal recovered through Chemical Formula 1 is attached to the negative electrode 321 . Accordingly, as shown in FIG. 5 , the anode 321 is washed with water and dried to recover the nickel metal.

<Experimental Example 2>

Table 3 shows the results of inductively coupled plasma analysis of the nickel metal and nickel compound recovered in <Preparation Examples 12 to 18>.

5 is a schematic diagram of a process in which nickel oxide is extracted in <Experimental Example 2>.

6 is a photograph of nickel oxide recovered according to <Preparation Example 18>.

pH of the electrolyte Total Yield (%) Nickel metal emptying (%) Nickel oxide percentage (%) Preparation 12 2.5 98.1 90.0 10.0 Preparation 13 3.0 97.8 85.0 15.0 Preparation 14 3.5 97.2 82.0 18.0 Preparation 15 4.0 98.1 75.0 25.0 Preparation 16 4.5 97.5 50.0 50.0 Preparation 17 5.0 98.4 25.0 75.0 Preparation 18 5.5 96.87 10.0 90.0

In <Experimental Example 2>, electrolysis was performed in an electrolyte solution of pH 2.5 to 5.5. Referring to Table 3, it can be seen that when the pH of the electrolyte is 2.5 to 5.5, nickel metal and nickel oxide are recovered from the electrolyte.

A process in which the nickel oxide is recovered will be described in more detail with reference to FIG. 5 and Chemical Formula 2 below. Nickel ions (Ni ²⁺ ) dissolved in the nickel solution move to the negative electrode tank 320 , meet hydroxide ions (OH ⁻ ) in the negative electrode 321 , and are recovered as nickel oxide through the following Chemical Formula 2 .

<Formula 2>

Ni ²⁺ + OH ^- → NiO + H ⁺

The nickel oxide recovered through Chemical Formula 2 is precipitated in the negative electrode tank 320 . Accordingly, the nickel oxide is recovered in the form shown in FIG. 6 after the electrolyte in the cathode tank 320 is filtered through a filter, the filtered material is washed with water, and dried.

Meanwhile, at the pH of 2.5 to 5.5, nickel metal and nickel oxide are simultaneously extracted in the negative electrode tank 320 , but the nickel metal is attached to the negative electrode 321 , whereas the nickel oxide is precipitated in the negative electrode bath 320 . Therefore, even when extracted at the same time, it can be extracted with a relatively high purity.

<Experimental Example 3>

Table 4 shows the results of inductively coupled plasma analysis of the nickel metal and nickel compound recovered in <Preparation Examples 19 to 20>.

7 is a schematic diagram of a process in which nickel carbonate is extracted in <Experimental Example 3>.

8 is a photograph of nickel carbonate recovered according to <Preparation Example 19>.

pH of the electrolyte Total Yield (%) Nickel metal emptying (%) Nickel carbonate percentage (%) Preparation 19 5.0 95.1 0.0 100.0 Preparation 20 5.5 96.87 0.0 100.0

In <Experimental Example 3>, electrolysis was performed at pH 5.0 to 5.5 of the electrolyte. In addition, sodium carbonate was added to the electrolyte solution as a pH adjuster. Referring to Table 4, it can be confirmed that nickel carbonate can be recovered when the electrolyte contains sodium carbonate.

A process in which the nickel carbonate is recovered will be described in more detail with reference to FIG. 7 and Chemical Formulas below. Nickel ions (Ni ²⁺ ) dissolved in the nickel solution move to the negative electrode tank 320 , meet sodium carbonate in the negative electrode 321 , and are recovered as nickel carbonate through Chemical Formula 3 below.

<Formula 3>

Ni ²⁺ + Na ₂ CO ₃ → NiCO ₃ + 2Na ⁺

The nickel carbonate recovered through Chemical Formula 2 is precipitated in the negative electrode tank 320 . Accordingly, the nickel carbonate is recovered in the form shown in FIG. 8 after the electrolyte in the negative electrode tank 320 is filtered through a filter, the filtered material is washed with water, and dried.

<Experimental Example 4>

Table 5 shows the results of inductively coupled plasma analysis of the nickel metal and nickel compound recovered in <Preparation Examples 21 to 30>.

9 is a schematic diagram of a process in which nickel hydroxide is extracted in <Experimental Example 4>

10 is a photograph of nickel hydroxide recovered according to <Preparation Example 30>.

pH Total Yield (%) Nickel metal ratio (%) Nickel hydroxide ratio (%) Preparation 21 6 98.5 5.0 95.0 Preparation 22 6.5 97.8 1.0 99.0 Preparation 23 7 98.4 0.5 99.5 Preparation 24 7.5 98.1 0.1 99.9 Preparation 25 8 98.5 0.0 100.0 Preparation 26 8.5 98.8 0.0 100.0 Preparation 27 9 97.95 0.0 100.0 Preparation 28 9.5 97.4 0.0 100.0 Preparation 29 10.5 98.2 0.0 100.0 Preparation 30 11.0 98 0.0 100.0

In <Experimental Example 4>, electrolysis was performed at pH 7 or higher of the electrolyte. Referring to Table 5, it can be confirmed that nickel hydroxide can be recovered when the pH of the electrolyte is 7.0 or higher.

A process in which the nickel hydroxide is recovered will be described in more detail with reference to FIG. 9 and Chemical Formula 4 below. Nickel ions (Ni ²⁺ ) dissolved in the nickel solution move to the negative electrode tank 320 , meet hydroxide ions in the negative electrode 321 , and are recovered as nickel hydroxide through Chemical Formula 4 below.

<Formula 4>

Ni ²⁺ + 2(OH) ^- → Ni(OH) ₂

The nickel hydroxide recovered through Chemical Formula 4 is precipitated in the negative electrode tank 320 . Accordingly, the nickel hydroxide is recovered in the form shown in FIG. 10 after the electrolyte solution in the negative electrode tank 320 is filtered through a filter, the filtered material is washed with water, and dried.

100: dissolving unit 200: filtration unit
210: filter 220: ion exchange resin
300: extraction unit 310: anode tank
311: positive electrode 320: negative electrode bath
321: cathode 330: cation exchange diaphragm
400: recovery unit 500: pH control unit

Claims (13)

a dissolving unit 100 in which a nickel raw material is dissolved in a solvent to form a nickel solution;
a filtration unit 200 including an ion exchange resin 220 for filtering impurities in the nickel solution;
An anode tank 310, which receives the nickel solution from which impurities have been filtered, and is provided with an anode 311, a cathode tank 320 and a cathode tank 320 and anode tank 310 and a cathode tank ( and a cation exchange diaphragm 330 partitioning 320), and when power is applied to the positive electrode 311 and the negative electrode 321, nickel metal or nickel compound is selectively extracted from the negative electrode tank 320 ( 300);
a recovery unit 400 comprising a negative electrode 321 from which the extracted nickel metal is recovered and a second recovery unit 420 from which the nickel compound is recovered; and
a pH adjusting unit 500 for adjusting the pH of the electrolyte injected into the cathode tank 320; including,
Depending on the pH adjusted by the pH adjusting unit 500 , nickel metal is recovered only from the negative electrode 321 , or nickel metal or a nickel compound is recovered from the negative electrode 321 and the second recovery unit 420 , respectively, or , the nickel compound is recovered only in the second recovery unit 420,
When the nickel compound is recovered only from the second recovery unit 420 , an additive is selectively added to the negative electrode tank 320 , and nickel carbonate or nickel hydroxide is recovered from the second recovery unit 420 . or a nickel compound recovery device.
delete delete The method of claim 1,
The pH adjusting unit 500 is a nickel metal or nickel compound recovery device for adding a pH adjusting agent to the negative electrode tank 320 to the negative electrode tank 320 .
delete A method for recovering nickel metal or nickel compound using the recovery device of claim 1, comprising:
A dissolution step (S100) in which the dissolving unit 100 dissolves a nickel raw material in a solvent to form a nickel solution;
a filtration step (S200) in which the filtering unit 200 filters impurities in the nickel solution;
A pH adjusting step (S300) in which the pH adjusting unit 500 adjusts the pH of the electrolyte injected into the negative electrode tank 320;
In the extraction unit 300, cations are exchanged through a cation exchange diaphragm 330 between the nickel solution in which the impurities introduced into the anode tank 310 are filtered and the electrolyte input into the cathode tank 320, and the cathode tank ( Extraction step (S400) of extracting at least one of nickel metal or nickel compound in 320); and
a recovery step (S500) in which the recovery unit 400 recovers at least one of the extracted nickel metal or nickel compound; including,
In the extraction step (S400) and the recovery step (S500),
According to the pH adjusted by the pH adjusting unit 500 in the pH adjusting step (S300), nickel metal is extracted and recovered only from the negative electrode 321 or from the negative electrode 321 and the second recovery unit 420 . Nickel metal or nickel compound is extracted and recovered, respectively, or nickel compound is extracted and recovered only in the second recovery unit 420,
When the nickel compound is extracted and recovered only from the second recovery unit 420 , the nickel additive is selectively added to the negative electrode tank 320 so that nickel carbonate or nickel hydroxide is recovered from the second recovery unit 420 . Metal or nickel compound recovery method.
delete delete delete 7. The method of claim 6,
In the pH adjustment step (S300),
When the pH adjusting unit 500 adjusts the pH of the electrolyte injected into the negative electrode tank 320 to 2.0 or less, the nickel metal in the negative electrode tank 320 in the extraction step (S400) and the recovery step (S500) is extracted,
When the pH adjusting unit 500 adjusts the pH of the electrolyte injected into the negative electrode bath 320 to 2.5 to 5.5, nickel metal and nickel oxide are extracted from the negative electrode bath 320 in the extraction step (S400). ,
When the pH adjusting unit 500 adjusts the pH of the electrolyte injected into the negative electrode bath 320 to 5.0 to 5.5 and sodium carbonate is added to the negative electrode bath 320, the negative electrode bath in the extraction step (S400) Nickel carbonate is extracted in (320),
When the pH control unit 500 adjusts the pH of the electrolyte injected into the negative electrode bath 320 to 7.0 or higher, nickel metal or nickel from which nickel hydroxide is extracted from the negative electrode bath 320 in the extraction step (S400) Methods of compound recovery.
delete delete delete

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