Electrode and production method therefor, and production method for regenerated electrode

Abstract

An electrode for electrolytic fluorination according to the present invention contains nickel as a base material, and has a fluorine content of less than 1,000 ppm. The electrode preferably has, in atleast a surface portion thereof, a nickel content of 99 mass% or more, an iron content of 400 ppm or less, a copper content of 250 ppm or less, and a manganese content of 1000 ppm or less. The production method for the electrode according to the present invention comprises disposing a nickel base material electrode as a cathode in a nickel plating bath, and applying nickel plating to the nickel base material electrode by an electrolytic nickel plating method, wherein (1) a nickel component which has precipitated in a molten salt or which has deposited on a cathode in a nitrogen trifluoride production step performed by molten salt electrolysis using a nickel base material anode, or said nickel base material anode, is used an anode, or (2) said nickel base material anode is used as a cathode.

Description

technical field

[0001] The present invention relates to an electrode which uses nickel as a base material and is used for fluorinating a compound by electrolysis, and a method for producing the same. Background technique

[0002] Conventionally, in the process of fluorinating a compound by electrolysis (hereinafter also referred to as "electrolytic fluorination process"), an electrode having nickel as a base material (hereinafter also referred to as "nickel base material electrode") is often used.

[0003] As one of the electrolytic fluorination steps, the production of nitrogen trifluoride is mentioned. For the production of nitrogen trifluoride by the electrolytic method, nitrogen trifluoride is produced by, for example, ammonium fluoride-hydrogen fluoride molten salt electrolysis using the following reaction formula. When carbon is used for the anode, carbon tetrafluoride is by-produced, but when nickel is used for the anode, this by-product is not produced, and high-pur...

Examples

Embodiment 1

[0102] (1) Nickel component recovery (production of nitrogen trifluoride)

[0103] As the anode and the cathode, respectively use a nickel plate with a nickel purity of 99% by mass, and use ammonia and anhydrous hydrofluoric acid to prepare ammonium fluoride-hydrogen fluoride-based molten salt NH in an electrolytic cell. 4 F·1.8HF, the passing temperature is 100℃, the current density is 8A / dm 2 Nitrogen trifluoride was produced with a current efficiency of 65% by molten salt electrolysis under certain conditions. During this production, the nickel component precipitated at the cathode is stripped and recovered. The area of ​​the anode after nitrogen trifluoride production is 70% or more of the electrode area before use.

[0104] (2) Manufacture of regenerative electrodes

[0105] 170 g of nickel sulfate hexahydrate, 32 g of nickel chloride hexahydrate, and 21 g of boric acid were dissolved in 0.7 L of pure water to prepare a plating bath. As the cathode, a nickel electrode...

Embodiment 2

[0112] (1) Nickel component recovery (production of nitrogen trifluoride)

[0113] As the anode and cathode, nickel electrodes with a nickel purity of 99% by mass were used, and ammonium fluoride-hydrogen fluoride-based molten salt NH was prepared in an electrolytic cell using ammonia and anhydrous hydrofluoric acid. 4 F·1.8HF, the passing temperature is 120°C, the current density is 5A / dm 2 Nitrogen trifluoride was produced with a current efficiency of 65% by molten salt electrolysis under certain conditions. During this production, the nickel component precipitated at the cathode is stripped and recovered. The area of ​​the anode after nitrogen trifluoride production is 50% or more of the electrode area before use.

[0114] (2) Manufacture of regenerative electrodes

[0115] 36.1 kg of nickel sulfate hexahydrate, 7.1 kg of nickel chloride hexahydrate, and 5.0 kg of boric acid were dissolved in pure water in a 150 L electrolytic cell whose inner surface was coated with Tef...

Embodiment 3

[0122] (1) Nickel component recovery (production of nitrogen trifluoride)

[0123] It operates similarly to Example 2.

[0124] (2) Manufacture of regenerative electrodes

[0125] Instead of the recovered nickel component used in (2) of Example 2, the cathode itself used in the manufacture of nitrogen trifluoride in (1) of Example 3 was used for the anode as nickel for dissolution. A regenerative electrode was fabricated under the same conditions as in Example 2. The resulting regenerative electrode has a mass increased by 90% relative to the consumable electrode used as a cathode. As a result of measurement by ion chromatography under the above conditions, the fluoride ion concentration in the plating bath at the end time was 0.8 g / L. Analysis of a part of the produced regenerative electrode by X-ray diffraction revealed that it was metallic nickel, and no fluorine components such as nickel fluoride were detected. As a result of analysis using the X-ray microanalyzer (acc...

technical field

[0001] The present invention relates to an electrode which uses nickel as a base material and is used for fluorinating a compound by electrolysis, and a method for producing the same. Background technique

[0002] Conventionally, in the process of fluorinating a compound by electrolysis (hereinafter also referred to as "electrolytic fluorination process"), an electrode having nickel as a base material (hereinafter also referred to as "nickel base material electrode") is often used.

[0003] As one of the electrolytic fluorination steps, the production of nitrogen trifluoride is mentioned. For the production of nitrogen trifluoride by the electrolytic method, nitrogen trifluoride is produced by, for example, ammonium fluoride-hydrogen fluoride molten salt electrolysis using the following reaction formula. When carbon is used for the anode, carbon tetrafluoride is by-produced, but when nickel is used for the anode, this by-product is not produced, and high-pur...

Examples

Embodiment 1

[0102] (1) Nickel component recovery (production of nitrogen trifluoride)

[0103] As the anode and the cathode, respectively use a nickel plate with a nickel purity of 99% by mass, and use ammonia and anhydrous hydrofluoric acid to prepare ammonium fluoride-hydrogen fluoride-based molten salt NH in an electrolytic cell. 4 F·1.8HF, the passing temperature is 100℃, the current density is 8A / dm 2 Nitrogen trifluoride was produced with a current efficiency of 65% by molten salt electrolysis under certain conditions. During this production, the nickel component precipitated at the cathode is stripped and recovered. The area of ​​the anode after nitrogen trifluoride production is 70% or more of the electrode area before use.

[0104] (2) Manufacture of regenerative electrodes

[0105] 170 g of nickel sulfate hexahydrate, 32 g of nickel chloride hexahydrate, and 21 g of boric acid were dissolved in 0.7 L of pure water to prepare a plating bath. As the cathode, a nickel electrode...

Embodiment 2

[0112] (1) Nickel component recovery (production of nitrogen trifluoride)

[0113] As the anode and cathode, nickel electrodes with a nickel purity of 99% by mass were used, and ammonium fluoride-hydrogen fluoride-based molten salt NH was prepared in an electrolytic cell using ammonia and anhydrous hydrofluoric acid. 4 F·1.8HF, the passing temperature is 120°C, the current density is 5A / dm 2 Nitrogen trifluoride was produced with a current efficiency of 65% by molten salt electrolysis under certain conditions. During this production, the nickel component precipitated at the cathode is stripped and recovered. The area of ​​the anode after nitrogen trifluoride production is 50% or more of the electrode area before use.

[0114] (2) Manufacture of regenerative electrodes

[0115] 36.1 kg of nickel sulfate hexahydrate, 7.1 kg of nickel chloride hexahydrate, and 5.0 kg of boric acid were dissolved in pure water in a 150 L electrolytic cell whose inner surface was coated with Tef...

Embodiment 3

[0122] (1) Nickel component recovery (production of nitrogen trifluoride)

[0123] It operates similarly to Example 2.

[0124] (2) Manufacture of regenerative electrodes

[0125] Instead of the recovered nickel component used in (2) of Example 2, the cathode itself used in the manufacture of nitrogen trifluoride in (1) of Example 3 was used for the anode as nickel for dissolution. A regenerative electrode was fabricated under the same conditions as in Example 2. The resulting regenerative electrode has a mass increased by 90% relative to the consumable electrode used as a cathode. As a result of measurement by ion chromatography under the above conditions, the fluoride ion concentration in the plating bath at the end time was 0.8 g / L. Analysis of a part of the produced regenerative electrode by X-ray diffraction revealed that it was metallic nickel, and no fluorine components such as nickel fluoride were detected. As a result of analysis using the X-ray microanalyzer (acc...

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