KR100513855B1 - Method for Treatment of Ni Containing Solution from Recycling Process of FeCl3 Etching Solution - Google Patents

Abstract

The present invention is FeCl ₃ etchant relates to a processing method of a Ni-containing solution resulting from the recycling process, FeCl ₃ in a solution containing Ni generated in the etching liquid recycle process, 0.5 of Fe (+2) ion molar amount present in the solution 2 Administering hydrogen peroxide by an amount and administering alkali until the pH reaches 2.5-4 to produce Fe (OH) ₃ and filtering it; And adding alkali to the filtered solution to adjust the pH to a range of 6.0 to 10.0 to produce a hydroxide of Chemical Formula 1; providing a method for treating a Ni-containing solution generated in a FeCl ₃ etching solution recycling process comprising: do.

[Formula 1]

(Ni, xMn1-x) Cly (OH) 2-y (where 0 <x, y <1)

According to the present invention, the Fe and Mn impurities present in the waste solution containing Ni generated in the FeCl ₃ etching solution recycling process can be effectively separated and purified, and the separated and purified solution can be separated into stainless steel, plating material, and utility nickel (Ni content> 97%) can be recycled as a raw material for various chemical products.

Description

Method for Treatment of Ni Containing Solution from Recycling Process of FeCl3 Etching Solution}

The present invention relates to a method for separating and purifying impurities such as Mn and Fe present in a Ni-containing solution, and more particularly, secondary waste generated from a process of recycling an etching waste liquid generated in a shadow mask manufacturing process of an electronics company. The present invention relates to a method for effectively separating Mn and Fe present in a phosphorus Ni-containing solution and recycling the high-quality Ni compound and etching solution.

In order to facilitate the understanding of the present invention, a solution containing Ni, which is a secondary waste generated in a process of recycling an etching waste liquid generated in a shadow mask manufacturing process, will be described first.

The shadow mask is manufactured through a process of localizing a Ni-containing Fe alloy, that is, an Invar alloy, with FeCl ₃ etching solution. In the continuous etching operation, the Invar alloy base material is dissolved and the FeCl ₂ and NiCl ₂ are generated in the solution according to Schemes 1 and 2 as follows.

Scheme 1

2FeCl ₃ + Ni = 2FeCl ₂ + NiCl ₂

Scheme 2

2FeCl ₃ + Fe = 3FeCl ₂

Therefore, if the work progresses to some extent, the content of FeCl ₂ and NiCl ₂ increases, so that the etching ability decreases. This is said to increase the fatigue of the solution. Therefore, if the FeCl ₂ and NiCl ₂ incorporation increases above a certain concentration for fatigue control, the solution should be discarded and a new FeCl ₃ solution should be used. The generated etching waste solution is subjected to Fe powder treatment, Ni is replaced by Fe powder, and then removed. The solution is chlorinated and recycled into FeCl ₃ (Japanese Patent No. 95-87474). This relates to a method of electrochemically replacing and depositing Ni ions produced by Scheme 1, and the scheme thereof is shown in Scheme 3 below.

Scheme 3

NiCl ₂ + 2Fe = FeNi + FeCl ₂

FeCl ₂ produced in Schemes 2 and 3 is oxidized to Cl ₂ and recycled to etch solution with FeCl ₃ .

On the other hand, the amount of FeCl ₂ produced by the reaction schemes 2 and 3 continues to increase, and thus the limit of recycling of FeCl ₃ through the reaction scheme 3 has been reached. Recently, a solvent extraction method for separating Ni and iron in solution instead of the iron powder input method has been attempted. . However, even with such a solvent extraction method, FeCl ₃ is recovered, but a process-generated waste solution having a large amount of Ni in Table 1 is generated.

TABLE 1 Components of Waste Solution from Solvent Extraction for FeCl ₃ Etch Recovery

                                                                 (Unit; ppm).

Ni Mn Fe Na Mg Ca 29000 450 12500 60 20 12

As can be seen from Table 1, Ni (29200 ppm (mg / liter) = 0.5 mol / liter) is usually the main component in the waste solution generated in the solvent extraction process for recovering FeCl ₃ etch solution. As impurities, Fe (12500 ppm = 0.22 mol / liter) is the main impurity, Mn (450 ppm = 0.88 mol / liter) is included in a considerable amount, and other small amounts of alkaline ions are included.

The inventors have previously filed a technique for dissolving FeNi sludge produced by Scheme 3 and separating it into FeOOH and high purity Ni (OH) ₂ (Korean Patent Application 98-56797). Also, to obtain high purity nickel oxide, which is a raw material for electronic materials and green pigments, from waste Ni anodes, co-precipitation oxidation through wet oxidation of Fe and Si and the use of Na ₂ CO ₃ as a neutralizing agent to prevent Cl mixing. It was previously filed (Korean Patent Application 98-57608 (registered 2003-401995)). However, the present invention does not introduce the separation and purification concept of Mn is a situation that requires the separation technology of Mn in the Ni-containing solution as shown in Table 1, and also has the disadvantage that Na ₂ CO ₃ used to reduce the Cl content is expensive.

The present inventors have developed and complemented the above patent through many studies to complete an economical separation and purification technology that effectively separates and purifies Fe and Mn impurities present in Ni-containing waste liquid and effectively recycles the separated and purified solution to suit the purpose. Was done.

An object of the present invention is to provide an economical separation and purification method for effectively separating and purifying Fe and Mn impurities present in a waste solution containing Ni generated in a FeCl ₃ etching solution recycling process, and effectively recycling the separated and purified solution for a purpose. .

According to the present invention, hydrogen peroxide is administered to the Ni-containing solution generated in the FeCl ₃ etching solution recycling process by 0.5 to 2 times the number of moles of Fe (+2) ions present in the solution, and alkali is added until the pH reaches 2.5 to 4. Administering to produce Fe (OH) ₃ and filtering it; And adding alkali to the filtered solution to adjust the pH to a range of 6.0 to 10.0 to produce a hydroxide of Formula 1 below. A method of treating a Ni-containing solution generated in a FeCl ₃ etching solution recycling process comprising: do.

[Formula 1]

(Ni, xMn1-x) Cly (OH) 2-y (where 0 <x, y <1)

Hereinafter, the present invention will be described in detail.

A method of separating Fe and Mn from Ni-containing waste solution generated in the FeCl ₃ etching solution recycling process, which is the core of the present invention, will be described.

First, for the separation of Fe FeCl ₃ etchant recycled process solution containing Ni Fe of the Fe of the Fe (+3) ions of the resulting 0.22 mole / L a review of the oxidation state of moles present arising from the 0.2 mol Fe (+2) The presence of 0.02 mol / liter of ions was confirmed by Fe ion analysis using an oxygen reduction potential (ORP). Hydrogen peroxide water was added as much as 0.5-2 times the number of moles of Fe (+2) ions present to oxidize Fe (+2) ions to Fe (+3) ions. Alkaline such as caustic soda, Ca (OH) ₂ and KOH is added to the solution to increase the pH of the solution up to 2.0-4.5, preferably up to 2.5-4.0. Fe (+3) and Fe (OH) ₃ forms Will precipitate. At this time, even a small amount of Cr is precipitated in the form of Cr (OH) ₃ . Filtration of the Fe (OH) ₃ precipitate left only Ni and Mn in the solution.

The alkali used in the present invention is not particularly limited thereto, but caustic soda, Ca (OH) ₂ , or KOH may be used.

On the other hand, the reason for limiting the pH to less than 2.5 to 4.0 when producing Fe (OH) ₃ is that Fe (OH) ₃ precipitation is poor at pH 2.5 or less, and impurities are not removed. Ni is precipitated at pH 4.0 and above. This is because loss of Ni occurs inside and Fe (OH) ₃ is not suitable for FeCl ₃ production by subsequent hydrochloric acid dissolution due to incorporation of Ni (OH) ₂ . Trace amount of Cr (OH) ₃ is not a problem because the fatigue of FeCl ₃ is not a cause of increase.

On the other hand, the present inventors added an alkali to the solution in which the Fe ions are removed to change the pH of the solution from 5.0 to 10.0 as a result of containing a cation such as Ni ions, Mn ions and anions such as Cl, OH The hydroxide composition was obtained according to the pH.

[Formula 1]

(Ni, xMn1-x) Cly (OH) 2-y (where 0 <x, y <1)

That is, the x, y value was confirmed through the component analysis of the hydroxide largely depends on the pH of the solution.

If the pH was less than 6, the amount of Ni hydroxide precipitate was very small (precipitation amount was less than the minimum amount of analysis) and could not be analyzed. Therefore, industrial use value is small. As the pH of the solution increases, both x and y decrease as precipitation increases. At pH = 6-7, the value is greater than x> 0.99, but in the 8.0-10.0 range it is x = 0.99-0.985. At pH = 5-7, y = 0.45-0.5, but increasing pH to 8-10.0 drops to y = 0-0.15, i.e., Mn in the hydroxide obtained at low pH with pH = 5-7.5 decreases and Ni Is increased but nickel hydroxide (Ni (OH) Cl) having a high incorporation of Cl is obtained. On the other hand, when the pH is raised to 7.5-10.0, the Cl content in nickel hydroxide is small but the Mn removal efficiency is slightly lowered. That is, when pH = 10.0, Mn is not removed at all and there is little change in initial concentration (0.5 mol; 0.08 mol) in nickel hydroxide. However, there is little Cl mixing, that is, y = 0.

As described above, since impurities contained in nickel hydroxide are different by pH adjustment, it is possible to manufacture products according to the required purity by using them as intermediate materials.

The hydroxide thus obtained can be used as a raw material for nickel and manganese-containing chemicals.

On the other hand, when the pH of the filtered solution is adjusted to the range of 6.0 ~ 7.5, the product is to produce a high purity Ni hydroxide with a small Mn content of x> 0.99 and y> 0.3 in the above formula. As such, high purity Ni hydroxide having a low Mn content is suitable for use as a plating raw material. For example, when the high purity Ni hydroxide is dissolved in hydrochloric acid, it may be usefully used as nickel chloride as a plating material. When hydrochloric acid is added to nickel hydroxide prepared by neutralizing in the pH range of 6.0-7.5, a high purity nickel chloride plating solution having a Mn content of less than 1% can be obtained. This can be expressed as a reaction equation as follows.

Scheme 4

Ni (OH) Cl + HCl = NiCl ₂ + H ₂ O

In addition, when the pH of the filtered solution is adjusted to the range of 9.0 to 10.0, the product has a low Cl content, that is, y <0.01 in the above formula, and the purity of NiO is 97-99%, that is, 0.97 <in the above formula. It will produce high purity Ni hydroxide with x <0.99. Furthermore, when the hydroxide is heat-treated at 500-800 ° C. to completely remove Cl, Ni hydroxide of higher purity is produced as shown in Chemical Formula 2 below.

[Formula 2]

Ni, x Mn1-xO (where 0 <x <1)

As such, high purity Ni hydroxide with little or no Cl content can be very useful for various chemical products based on nickel.

Meanwhile, nickel hydroxide prepared at pH = 9-10.0 contains Mn (maximum content 1.5%), but utility nickel (Ni content), which is used as a raw material for stainless steel, when nickel oxide is manufactured by heat treatment and dehydration thereof. 97%) It is possible to use nickel oxide (purity 98.5%) for manufacturing. This can be expressed as a reaction equation as follows.

Scheme 5

Ni _0.985 Mn _0.015 (OH) ₂ = Ni _0.985 Mn _0.015 O + H ₂ O

In particular, when the nickel hydroxide is heat-treated, the nickel hydroxide containing Cl generates a large amount of chlorine gas, which may cause problems such as corrosion of the facility and environment. That is, nickel hydroxide prepared at pH 8 or below is not suitable for the production of nickel oxide accompanying heat treatment by mixing Cl.

Therefore, it is preferable to minimize Cl, which means that if the neutralization pH is more than 9.0, the y value in the composition (NixMn1-x) Cly (OH) 2-y (0 <x, y <1) becomes 0.01 or less, so that chlorine gas is generated during heat treatment. Can be minimized.

Hereinafter, the present invention will be described in more detail with reference to the following examples.

Example 1

First, in order to separate Fe, the oxidation state of Fe present in the solution of Table 1 was investigated. As a result, 0.2 (2) mol / liter of Fe (+3) ions and 0.22 mol / liter of Fe (+2) and 0.02 mol / liter The presence was confirmed by Fe ion analysis using an oxygen reduction potential (ORP). One liter of waste solution containing Ni was administered with 0, 0.01, 0.02, 0.03 mol / liter of hydrogen peroxide, a liquid oxidant, to be 0-3 times the Fe (+2) ion concentration in the solution, and 10 mol / liter of KOH. Fe (OH) ₃ sludge was generated while changing the pH of the solution to 2-5. The solution was then filtered and the metal ion concentrations and impurity concentrations in the solution according to oxidant concentration and pH were investigated and are shown in Table 2.

[Table 2] Metal ion concentration and impurity concentration in solution according to oxidizer concentration and pH

Manufacture conditions Metal ion concentration (mg / liter) Remarks H ₂ O ₂ mole Maintenance pH Ni Fe Mn Comparative Example 1 0 3.5 27200 1100 410 Insufficient Fe removal Inventive Example 1 0.01 3.5 26500 9 405 Inventive Example 2 0.02 3.5 27000 0.5 or less 415 Comparative Example 2 0.03 3.5 26800 0.5 or less 400 Excess H ₂ O ₂ Comparative Example 3 0.02 1.5 27100 8550 400 Insufficient Fe removal Inventive Example 3 0.02 2.5 27000 10 405 Comparative Example 4 0.02 4.5 25500 0.5 or less 410 Ni (OH) ₂ incorporation

Ni solution Ni, Mn concentration was reduced due to the concentration decrease due to the addition of KOH alkali solution. Fe ions varied greatly depending on the treatment method. In the case of H ₂ O ₂ or more than 0.5 times the Fe (+2) ion concentration, the Fe concentration was reduced to 10 ppm or less, which is very low compared to the non-administered sample (Comparative Example 1). Administration of more than twice the number of moles of Fe (+2) ion no longer improved the Fe removal effect (Comparative Example 2).

This is represented by the chemical reaction shown in Scheme 6.

Scheme 6

2FeCl ₂ + 2HCl + H ₂ O ₂ = 2FeCl ₃ + 2H ₂ O

FeCl ₃ + 3NaOH = Fe (OH) ₃ + 3NaCl

If the holding pH is less than 2.5 (Comparative Example 3), Fe (OH) ₃ precipitation reaction is not so good Fe removal effect, Ni is precipitated when the pH is above 4.5 (Comparative Example 4).

Fe (OH) ₃ filtered in the present invention may be washed with water to remove the ionic phase Ni, Na, Cl and the like, and then reacted with concentrated hydrochloric acid to recover the FeCl ₃ (about 45% concentration) etching solution. However, when Ni (OH) ₂ is mixed with Fe (OH) ₃ as in Comparative Example 4, since a large amount of Ni is introduced into the FeCl 3 etchant, Fe (Ni) should be removed at a pH below 4.0 at which no Ni (OH) ₂ precipitation occurs.

Example 2

The pH of the solution was adjusted to 5-11 by administering KOH (10 mol / liter) to the solution from which Fe impurities were removed under the conditions of Inventive Example 1 of Example 1. A green precipitate formed in the solution. This precipitate was washed well to remove water soluble ions such as KCl and analyzed. The component was confirmed by quantitative chemical analysis that (NixMn1-x) Cly (OH) 2-y (0 <x, y <1) consisting of Ni, Mn, Cl, OH. The composition ratio of the precipitate, that is, x, y was confirmed to vary greatly according to the pH of the solution as shown in Table 3.

TABLE 3

Solution pH Quantitative Analysis Chemical compatibility x value y value Nickel Chloride Utility NiO Comparative Example 5 5.0 - - Insufficient sediment Insufficient sediment Inventive Example 4 6.0 0.995 0.500 Good y-value high (Excess Cl) Inventive Example 5 7.0 0.991 0.450 Good y-value high (Excess Cl) Comparative Example 6 8.0 0.987 0.150 x value is low (more than Mn) y-value high (Excess Cl) Inventive Example 7 9.0 0.985 0.010 x value is low (more than Mn) Good Inventive Example 8 10.0 0.985 0 x value is low (more than Mn) Good Comparative Example 7 11.0 0.985 0 x value is low (more than Mn) No Cl improvement

When the pH was less than 6 (Comparative Example 5), the amount of Ni hydroxide precipitated was very small (precipitated amount was less than the minimum amount analyzed) and thus could not be analyzed. Therefore, industrial use value is small. As the pH of the solution increases, both x and y decrease as precipitation increases. At pH = 6-7, the value is greater than x> 0.99, but in the 8.0-10.0 range it is x = 0.99-0.985. At pH = 5-7, y = 0.45-0.5, but increasing the pH to 8-10.0 drops to y = 0-0.15. In other words, the hydroxide obtained at a low pH of pH = 5-7.5 results in the reduction of Mn and increase of Ni, but Ni hydroxide (Ni (OH) Cl) containing a lot of Cl is obtained. On the other hand, when the pH is increased to 7.5-10.0, the Cl content in nickel hydroxide is small but the Mn removal efficiency is slightly lowered. That is, when pH = 10.0, Mn is not removed at all and there is little change in initial concentration (0.5 mol; 0.08 mol) in nickel hydroxide. However, there is little Cl mixing, that is, y = 0.

When hydrochloric acid is added to the nickel hydroxide (inventive material 4,5) prepared by neutralization in the pH range of 5.0-7.5, a high purity nickel chloride plating solution having a Mn content of less than 1% can be obtained. This can be expressed as a reaction equation as follows.

Scheme 4

Ni (OH) Cl + HCl = NiCl ₂ + H ₂ O

As a result of dissolving the nickel hydroxide cake of Inventive Materials 4 and 5 in concentrated hydrochloric acid (10 mol / liter), NiCl ₂ was obtained (Ni> 29.2%, Mn <300ppm), which corresponds to the NiCl ₂ solution for electroplating.

Meanwhile, nickel hydroxide (inventive material 7,8) prepared at pH = 9-10.0 contains Mn (maximum content of 1.5%), but is used as a common stainless raw material when manufacturing nickel oxide by heat treatment to dehydration. It can be used as nickel oxide (purity 98.5%) for the production of utility nickel (Ni content> 97%). This can be expressed as a reaction equation as follows.

 Scheme 5

Ni _0.985 Mn _0.015 (OH) ₂ = Ni _0.985 Mn _0.015 O + H ₂ O

In particular, nickel hydroxide, which contains Cl when heat-treating nickel hydroxide, generates a large amount of chlorine gas, which may cause problems such as corrosion of the facility and environment. In other words, nickel hydroxide prepared below pH 8 is not suitable for the production of nickel oxide involving heat treatment by Cl incorporation (Comparative Example 6).

Therefore, it is desirable to minimize Cl content for the production of nickel oxide. For this purpose, if the neutralization pH is set to 9.0 or more, the y value in the (NixMn1-x) Cly (OH) 2-y (0 <x, y <1) composition is 0.01. Chlorine gas can be minimized during heat treatment because it is less than (invention materials 7, 8). Even if the neutralizing pH is 10.0 or more (Comparative Example 7), there is no decrease in the y value, but rather, the neutralizing pH due to neutralization is less than 10 is sufficient.

When nickel hydroxide of the invention material 7,8 is heat-treated at 500 degreeC or more, Mn containing black nickel oxide (purity> 98%) can be manufactured. If the dehydration reaction is less than 500 ℃, and the color is mixed and sintering occurs above 800 ℃, 500-800 ℃ is most suitable.

According to the present invention, the Fe and Mn impurities present in the waste solution containing Ni generated in the FeCl ₃ etching solution recycling process can be effectively separated and purified, and the separated and purified solution can be separated into stainless steel, plating material, and utility nickel (Ni content> 97%) can be recycled as a raw material for various chemical products.

Claims (6)

To the Ni-containing solution generated in the FeCl ₃ etching solution recycling process, hydrogen peroxide was administered by 0.5 to 2 times the number of moles of Fe (+2) ions present in the solution, and alkali was administered until the pH reached 2.5 to 4 by Fe ( OH) ₃ to produce and filter it; And Adding alkali to the filtered solution to adjust the pH to a range of 6.0 to 10.0 to produce a hydroxide of Formula 1 below; Method for treating Ni-containing solution generated in the FeCl ₃ etching solution recycling process comprising a. [Formula 1] (Ni, xMn1-x) Cly (OH) 2-y (where 0 <x, y <1) The method of claim 1 wherein the hydroxide is used as a raw material for nickel and manganese containing chemicals. The method according to claim 1, wherein when the pH of the filtered solution is adjusted to be in the range of 6.0 to 7.5, the product produces high purity Ni hydroxide having a small Mn content as x> 0.99 and y> 0.3 in the above formula. . 4. The method of claim 3, wherein the hydroxide is dissolved in hydrochloric acid and used as nickel chloride as a plating material. The method of claim 1, wherein when adjusting the pH of the filtered solution in the range of 9.0 to 10.0, the product is low in Cl, that is y <0.01 in the formula, the purity of NiO is 97-99%, Producing a high purity Ni hydroxide with the formula 0.97 <x <0.99. The method of claim 5, wherein the hydroxide is further heat-treated at 500-800 ° C. to produce a high purity Ni hydroxide of Formula 2, wherein Cl is removed. [Formula 2] Ni, x Mn1-xO (where 0 <x <1)