Brief introduction

Chinese Name: fluoroboric acid

Foreign name: fluoroboric acid

Chinese alias: tetrafluoroboric acid, hydrofluoro boric acid

Molecular formula: HBF4

Relative molecular weight: 87.81

CAS No.: 16872-11-0

physical property

Appearance and character: colorless transparent liquid

Relative density (water = 1): 1.84 (48%)

Melting point (℃): - 90 ℃

Boiling point (℃): 130 ℃ (48%)

Relative vapor density (air = 1): 3.0

Main ingredients: 20.0% [1]

Flash point (℃): - 40 ° f [2]

Saturated vapor pressure (kPa): 0.67 (20 ℃)

Solubility: miscible with water, miscible with alcohol

Chemical property

Colorless transparent liquid. It is strongly acidic. It is partially hydrolyzed in water to form bf3oh -. It can form crystalline salt with metal. The refractive index (n20d) of 20% aqueous solution was 1.3284. It's tear jerky. It is highly corrosive. The commodity is usually 48% aqueous solution or 54% ether solution, which is flammable.

Functions and uses

It is used for cleaning oxide and silicate film on metal surface and corrosive agent, cleaning aluminum and alloy before electroplating. 2.5% solution is used for electrolytic polishing of pure aluminum and re washing solution for removing flux from metal substrate and electroplating parts. It is used as catalyst, preservative, chemical reagent for alkylation and polymerization, and raw material for preparing various fluoroborates[ 2]

It can be used as catalyst for acetaldehyde synthesis, metal surface cleaner, polishing agent for lead electrolysis, stabilizer of diazonium salt, etc; It can be used as stabilizer of diazonium salts and electrolytic industry; Used for cleaning metal surface and alloy before electroplating. It is composed of aluminum and steel phosphate passivation preservatives, the most suitable lead dissolving electrolyte for lead-acid batteries, enhancing the permeability of crude oil in oilfield exploitation, diazonium salt stabilizer and raw materials for various fluoroborates, and catalyst for alkylation and polymerization. Metal surface oxide, silicate film cleaning and corrosion agent. Especially for the cleaning of aluminum and alloy before electroplating, Electropolishing of pure aluminum, removal of solder from low activity metal substrate and re cleaning of electroplated parts, it is an important component of electroplating solution

Precautions for use

Risk overview

Health hazard: harmful to the body by inhalation, oral administration or absorption through the skin. It has strong irritation to eyes, skin, mucous membrane and respiratory tract. After inhalation, the patient may die of spasm, edema and inflammation of larynx and bronchus, chemical pneumonia and pulmonary edema. The symptoms of poisoning included burning, cough, wheezing, laryngitis, shortness of breath, headache, nausea and vomiting.

Explosion hazard: This product is non combustible, highly corrosive and irritating, and can cause burns to human body[ 1]

First aid measures

Skin contact: take off contaminated clothes immediately and rinse with plenty of flowing water for at least 15 minutes. See a doctor.

Eye contact: lift eyelids immediately and rinse thoroughly with plenty of flowing water or normal saline for at least 15 minutes. See a doctor.

Inhalation: quickly leave the scene to fresh air. Keep respiratory tract unobstructed. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately. See a doctor.

Ingestion: gargle with water and drink milk or egg white. See a doctor.

Fire fighting measures

Hazard characteristics: it burns immediately when meeting h foaming agent. When heated, it decomposes and releases toxic fluoride gas. It can corrode most metals and organic structures.

Harmful combustion products: hydrogen fluoride, boron oxide.

Fire fighting method: Firefighters must wear acid and alkali resistant fire fighting clothes. Extinguishing agent: carbon dioxide, sand.

Leakage emergency treatment

Emergency treatment: quickly evacuate the personnel from the contaminated area to the safe area, isolate them and strictly restrict their access. It is suggested that the emergency treatment personnel should wear self-contained positive pressure respirator and acid-base protective clothing. Do not touch the leakage directly. Cut off the leakage source as much as possible.

Small leakage: absorb or absorb with sand or other non combustible materials. It can also be washed with a large amount of water and diluted into the waste water system.

Large amount of leakage: build dike or dig pit to take in. Transfer to tank car or special collector by pump, recycle or transport to waste treatment site for disposal.

Handling and storage

Operation precautions: closed operation, pay attention to ventilation. The operation should be mechanized and automatic as far as possible. Operators must be specially trained and strictly abide by the operating procedures. It is recommended that operators wear self-priming filter gas mask (full mask), rubber acid and alkali resistant clothing and rubber acid and alkali resistant gloves. Prevent vapor leakage into the workplace air. Avoid contact with alkali. When carrying, it should be loaded and unloaded lightly to prevent the package and container from being damaged. Equipped with leakage emergency treatment equipment. Empty containers may contain harmful substances.

Storage precautions: store in a cool and ventilated warehouse. Keep away from fire and heat source. Keep the container sealed. It should be stored separately from alkali and avoid mixed storage. The storage area shall be equipped with leakage emergency treatment equipment and suitable storage materials.

Preparation

The hydrofluoric acid method is based on the theoretical amount of hydrofluoric acid and boric acid. Boric acid is slowly added into hydrofluoric acid under stirring, and the reaction temperature is controlled below 40 ℃. After heating, the mechanical stirring is stopped, and the product is placed at room temperature for more than 2 hours, and then filtered and purified to prepare fluoroboric acid. his

4HF+H3BO3→HBF3OH+HF+2H2O

HBF3OH+HF→HBF4+H2O

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