CN1386906A

CN1386906A - Process for removing Ni from waste etching FeCl3 solution containing Ni

Info

Publication number: CN1386906A
Application number: CN 02116014
Authority: CN
Inventors: 陈志传; 毛谙章; 覃祚观; 郑嘉辉; 秦建武
Original assignee: DANGEROUS WASTE TREATMENT STATION SHENZHEN CITY
Current assignee: Shenzhen Hazardous Waste Treatment Station Co., Ltd.
Priority date: 2002-04-23
Filing date: 2002-04-23
Publication date: 2002-12-25
Anticipated expiration: 2022-04-23
Also published as: CN1170004C

Abstract

A process for removing Ni from the used etching Ni-containing FeCl3 solution includes adding iron powder or fraky iron scales, reduction reaction, heating to 55-95 deg.C, adding iron powder and sulfur powder, precipitating 2-valence Ni, adding iron powder and sulfur or As compound or Sb compound for further precipitation, and filtering. Its advantages are high effect on recovering Ni and regenerating FeCl3 solution and low cost.

Description

Nickel removing method for nickel-containing ferric trichloride etching waste liquid

Technical Field

The invention relates to a nickel removal method for nickel-containing ferric trichloride etching waste liquid.

Background

Ferric chloride FeCl₃Are often used as etchants in the production of printed wiring boards and picture tubes for displays and televisions. In the production of shadow masks for picture tubes, FeCl is added during the etching process₃Reduction of etched metallic iron and nickel to FeCl₂Metallic nickel also being Ni²⁺The form enters into the etching solution, and FeCl is generated along with the progress of the etching process₃The concentration is gradually reduced, and the etching efficiency is also reduced. Therefore, the etching solution must be periodically replaced with fresh FeCl₃The etching solution replaces old etching solution, and used waste etching solution is discharged from the system, and Fe in the waste etching solution²⁺Can be regenerated by chlorine oxidation, but the etching waste liquid also contains a considerable amount of Ni²⁺Will affect the etching efficiency, and therefore Ni in the etching waste liquid must be removed²⁺。

The fundamental points of research work on such waste liquid treatment are: removing nickel in the waste liquid, and regenerating or utilizing the nickel and ferric trichloride. The basic treatment methods at present are: diaphragm electrolysis, evaporation concentration crystallization, iron powder (or iron sheet) reduction, electric reduction, fractional precipitation of alkali (such as sodium hydroxide and sodium carbonate), and extraction separation. Each of these methods has disadvantages, which are described below:

the diaphragm electrolysis method has complex equipment, high treatment cost and limited nickel and iron separation effect; evaporating, concentrating and crystallizing to obtain impure ferric trichloride or nickel chloride, i.e. the ferric trichloride contains nickel chloride and the nickel chloride contains ferric trichloride; the iron powder (or iron sheet) reduction method is used for obtaining mixed powder of nickel and iron, but the solution still contains high content of nickel, and high-quality iron powder is used; the fractional precipitation method of alkali (such as sodium hydroxide and sodium carbonate) has high cost and incomplete separation; the extraction separation method has high cost and incomplete extraction separation, and the regenerated ferric trichloride (to be evaporated and concentrated) has high nickel content.

The closest background to the present invention is the iron powder reduction process. The defects of the existing iron powder reduction method are as follows: in the process, expensive iron powder is used, meanwhile, the complete separation of ferronickel cannot be realized, and 30-1000ppm of nickel still exists in the regenerated ferric trichloride.

Disclosure of Invention

The invention aims to provide a nickel removing method of nickel-containing ferric trichloride etching waste liquid, which can remove nickel thoroughly and ensure that regenerated ferric trichloride can be applied to occasions with high requirements on nickel content indexes, aiming at the defects of the existing iron powder reduction method.

The purpose of the invention is realized as follows: the present invention includes the following sequence of steps,

(1) adding iron powder or scale iron sheet into the etching waste liquid to perform reduction reaction:

in this step, the amount of iron powder or scale iron added actually is generally 100% to 150% of the theoretical amount of addition thereof, and preferably 100% to 110% of the theoretical amount of addition thereof, which is Fe in theetching waste liquid³⁺And H⁺Half of the sum of the number of moles is calculated according to the following equation,

and

the iron powder can be selected from-60 mesh iron powder to avoid FeCl₂·4H₂0, and adding a proper amount of water by adjusting the concentration of regenerated ferric trichloride, wherein the reduction reaction time is generally 20-180 minutes, preferably 40-80 minutes;

(2) then heating the reaction mixture to 55-95 ℃, and then adding iron powder and sulfur powder into the reaction mixture to perform a precipitation reaction of divalent nickel:

in this step, the amount of iron powder added is generally Ni in the solution after the reaction in step (1)²⁺2 to 10 times of the mole number, the adding amount of the sulfur powder is generally Ni in the solution after the reaction in the step (1)²⁺2-10 times of the mole number, the iron powder can be-60 meshes of iron powder, the sulfur powder can be-200 meshes of sulfur powder, after stirring and reacting for 60-180 minutes, the step (3) can be directly carried out, filter residue can also be removed by filtration, the filter residue is used for further recycling nickel, and Ni in the mother liquor²⁺Is less than 100 ppm;

(3) then, adding iron powder and sulfur powder into the reaction mixture at the temperature of between 55 and 95 ℃ or continuously adding the iron powder and the sulfur powder, wherein the iron powder can be-60-mesh iron powder, the sulfur powder can be-200-mesh sulfur powder, and the adding amount of the iron powder is generally N in the solution after the step (2)i²⁺2-20 times of the mole number, the adding amount of the sulfur powder is generally Ni in the solution after the step (2)²⁺1 to 20 times of the mole number, stirring and reacting for 60 to 180 minutes,

or adding iron powder and arsenic compound, wherein the iron powder can be-60 mesh iron powder, the arsenic compound can be one of calcium arsenate, sodium hydrogen arsenate, sodium arsenite, ferric arsenite, arsenic trioxide, arsenic pentoxide, estramune and androstane, and the iron powder is added into the solution after step (2)²⁺2-20 times of the mole number, the adding amount of the arsenic compound is generally Ni in the solution after the step (2)²⁺1 to 20 times of the mole number, stirring and reacting for 60 to 180 minutes,

or adding iron powder and antimony compound, wherein the iron powder can be-60-mesh iron powder, the antimony compound can be one of sodium antimonate, antimony trichloride, antimony pentachloride, antimony oxychloride, antimony trioxide, antimony pentoxide and potassium antimony tartrate, and the adding amount of the iron powder is generally Ni in the solution after the step (2)²⁺2-20 times of the mole number, the adding amount of the antimony compound is generally Ni in the solution after the step (2)²⁺1 to 10 times of the mole number, stirring and reacting for 60 to 180 minutes,

this step is further carried out the precipitation reaction of divalent nickel, and then the reaction is filtered, and the mother liquor isNi²⁺The content is less than 10 ppm.

The invention has the technical effects that: (1) the invention can effectively separate nickel from the ferric trichloride etching waste liquid, so that the Ni in the regenerated ferric trichloride solution²⁺The content of the nickel is lower than 10ppm, so that high-quality liquid ferric trichloride is regenerated, and meanwhile, nickel can be effectively recovered, thereby eliminating environmental pollution and changing waste into valuable; (2) the invention has low cost and high efficiency; (3) the invention has simple and reliable process, strong operability, safety and small equipment investment.

The present invention is further illustrated by the following examples.

Detailed Description

The first embodiment is as follows:

the nickel-containing ferric trichloride etching waste liquid generated by a certain display shadow mask production enterprise is processed,

nickel-containing ferric trichloride etching waste liquid components: fe³⁺：212.6g/L

Fe²⁺：4.92g/L

Ni²⁺：22.97g/L

H⁺：0.1g/L

4000L of waste liquid is added into the reaction tank, 2000L of water is added, and 446Kg of iron powder with a particle size of-100 meshes is added in 25 minutes in four times. The concentration of nickel in the solution was analyzed after 60 minutes of reaction from the start of the addition of the iron powder meter. Then heating the reaction mixture to 90 ℃, adding 247Kg of iron powder with 100 meshes and 141Kg of sulfur powder with 325 meshes in two times, stirring and reacting for 90 minutes at 90-95 ℃, filtering, and sending filter residues to a nickel sulfate production section. Heating the mother liquor to 90 ℃, adding 5Kg of iron powder with a particle size of-100 meshes and 3Kg of sulfur powder with a particle size of-325 meshes at one time, stirring and reacting for 90 minutes at the temperature of 90-95 ℃, filtering, sending filter residues to a nickel sulfate production working section, and adding Ni in the mother liquor²⁺The concentration is less than 10ppm, and the liquid ferric trichloride is produced in chlorination section.Example two: treatment of the same nickel-containing ferric chloride etching waste liquid as in example one

Adding 4000L of waste liquid into a reaction tank, adding 2000L of water, adding 480Kg of iron powder with a particle size of-100 meshes within 25 minutes in four times, reacting for 40 minutes after the iron powder is added, and analyzing Ni in the solution²⁺The concentration of (c). Heating the reaction mixture to 90 ℃, adding 494Kg of iron powder with 100 meshes and 141Kg of sulfur powder with 325 meshes in two times, stirring and reacting for 90 minutes at 90-95 ℃, filtering, and sending filter residues to a nickel sulfate production section. Heating the mother liquor to 90 ℃, adding 5Kg of iron powder with a particle size of-100 meshes and 3Kg of sodium arsenite at one time, stirring at 90-95 ℃ for reaction for 90 minutes, filtering, and adding Ni in the mother liquor²⁺The concentration is less than 10ppm, and the liquid ferric trichloride is produced in chlorination section. Example three: treatment of the same nickel-containing ferric chloride etching waste liquid as in example one

4000L of waste liquid is added into the reaction tank, 2000L of water is added, 462Kg of iron powder with a grain size of-100 meshes is added in 25 minutes in four times, and the iron powder is added from the beginningIn time, after 80 minutes of reaction, the solution was analyzed for Ni²⁺The concentration of (c). Heating the reaction mixture to 90 ℃, adding 247Kg of iron powder with a particle size of-100 meshes and 282Kg of sulfur powder with a particle size of-325 meshes in two times, stirring at 90-95 ℃ for reaction for 90 minutes, filtering, and sending filter residues to a nickel sulfate production section. Heatingthe mother liquor to 90 ℃, adding 5Kg of-100-mesh iron powder and 6Kg of antimony potassium tartrate at one time, stirring at 90-95 ℃ for reaction for 90 minutes, filtering, and adding Ni in the mother liquor²⁺The concentration is less than 10ppm, and the liquid ferric trichloride is produced in chlorination section.

In the three examples described above, the iron powder added in the first step four times over 25 minutes may be replaced by a scaly iron scale.

Claims

1. A nickel removal method for nickel-containing ferric trichloride etching waste liquid is characterized in that: comprises the following steps in the following sequence,

(1) adding iron powder or scale iron sheet into the etching waste liquid for reduction reaction;

(2) then heating the reaction mixture to 55-95 ℃, and then adding iron powder and sulfur powder into the reaction mixture to perform a precipitation reaction of divalent nickel;

(3) then, iron powder and sulfur powder, or iron powder and arsenic compound, or iron powder and antimony compound are added into the reaction mixture at 55-95 ℃, and then the precipitation reaction of divalent nickel is further carried out, and then the reaction mixture is filtered.

2. The nickel-removing method of nickel-containing ferric trichloride etching waste liquid according to claim 1, characterized in that: in the reduction reaction of the step (1), the actual adding amount of the iron powder or the scale-like iron sheet is 100 to 150 percent of the theoretical adding amount of the iron powder or the scale-like iron sheet, and the theoretical adding amount of the iron powder or the scale-like iron sheet is Fe in the etching waste liquid³⁺And H⁺Half of the sum of the moles.

3. The method for removing nickel from nickel-containing ferric trichloride etching waste liquid according to claim 1 or 2, characterized in that: the time of the reduction reaction in the step (1) is 20-180 minutes.

4. The method for removing nickel from nickel-containing ferric trichloride etching waste liquid according to claim 1 or 2, characterized in that: the adding amount of the iron powder in the step (2) is Ni in the solution after the reaction in the step (1)²⁺2-10 times of the mole number, and the addition amount of the sulfur powder is Ni in the solution after the reaction in the step (1)²⁺2-10 times of the mole number, stirring for reaction for 60-180 minutes, and filtering to remove filter residues.

5. The nickel-removing method of nickel-containing ferric trichloride etching waste liquid according to claim 1, characterized in that: and (3) filtering after the precipitation reaction in the step (2), and removing filter residues.

6. The method for removing nickel from nickel-containing ferric trichloride etching waste liquid according to claim 1 or 2The method is characterized in that: the adding amount of the iron powder in the step (3) is Ni in the solution after the step (2)²⁺2-20 times of the mole number, and the addition amount of the sulfur powder is Ni in the solution after the step (2)²⁺Stirring and reacting for 60-180 minutes, wherein the molar number of the reaction solution is 1-20 times that of the raw materials.

7. The method for removing nickel from nickel-containing ferric trichloride etching waste liquid according to claim 1 or 2, characterized in that: the adding amount of the iron powder in the step (3) is Ni in the solution after the step (2)²⁺2-20 times of the mole number, and the adding amount of the arsenic compound is Ni in the solution after the step (2)²⁺Stirring and reacting for 60-180 minutes, wherein the molar number of the reaction solution is 1-20 times that of the raw materials.

8. The method for removing nickel from nickel-containing ferric trichloride etching waste liquid according to claim 1 or 2, characterized in that: the adding amount of the iron powder in the step (3) is Ni in the solution after the step (2)²⁺2-20 times of the mole number, and the addition amount of the antimony compound is Ni in the solution after the step (2)²⁺Stirring and reacting for 60-180 minutes, wherein the molar number of the reaction solution is 1-10 times that of the raw materials.

9. The nickel-removing method of nickel-containing ferric trichloride etching waste liquid according to claim 1, characterized in that: the arsenic compound is selected from one of calcium arsenate, sodium hydrogen arsenate, sodium arsenite, ferric arsenate, ferric arsenite, arsenic trioxide, arsenic pentoxide, estramum and androsterone.

10. The nickel-removing method of nickel-containing ferric trichloride etching waste liquid according to claim 1, characterized in that: the antimony compound is one of sodium antimonate, antimony trichloride, antimony pentachloride, antimony oxychloride, antimony trioxide, antimony pentoxide and antimony potassium tartrate.