Ammonium fluoride

Ammonium hydrogen fluoride

At room temperature, ammonium hydrogen fluoride appears as white or colorless orthorhombic crystal with slight sour. It is poisonous! It is slightly soluble in alcohol, easily soluble in cold water while subjecting to decomposition in hot water. Its aqueous solution is strongly acidic. It is obtained through the neutralization between the anhydrous hydrofluoric acid and ammonia. It can corrode glass and is corrosive to the skin. It can be used as a chemical reagent, glass etching agent (with participation of hydrofluoric acid), disinfectants and preservatives in fermentation industry, solvent for making metal beryllium via beryllium oxide and surface treatment agent of silicon steel sheet. It can also be used for the manufacturing of ceramics, magnesium alloy, the cleaning and scaling of boiler feed water systems and steam generating system as well as the acid treatment agent for oil sand. It is also used as the component of alkylation and isomerization catalyst.
The production process of ammonium hydrogen fluoride is generally first generating ammonium fluoride followed by further sending through hydrogen fluoride to generate ammonium hydrogen fluoride. If not properly managed, it will become a mixture of ammonium fluoride and ammonium hydrogen fluoride with ammonium fluoride being easily decomposed into ammonium hydrogen fluoride.
This information is edited by Xiongfeng Dai from Chemicalbook.

Toxicity

This product is toxic. The operator must wear protective equipment. See the remaining protective measures in the part of ammonium hydrogen fluoride.

Chemical Properties

It appears as colorless phyllodes or needle-like crystals and forms hexagonal columnar crystals after being subject to sublimation. It is easily deliquescent. It is easily soluble in water with aqueous solution being acidic. It is soluble in alcohol but insoluble in acetone and liquid ammonia.

Uses

It can be used as glass etching agent, the chemical polishing agent on the metal surface, preservatives and disinfectants of brewing and fiber mordant as well as for extracting rare metals.
It can be used as reagents for the analysis, masking agents and preservatives.
It can be applied to wood preservation, glass engraving and precipitation agent for the complexometric titration of the aluminum, extraction of rare elements as well as spot analysis of zirconium.

Production method

Liquid-phase method: to lead or plastic container, put certain amount of hydrofluoric acid. Cool water in the outer container and slowly introduce ammonia gas under stirring until the pH value of reaction solution reaches about 4. The reaction liquid further goes through cooling and crystallization, centrifugation, air drying to obtain ammonium fluoride products.
NH3 + HF → NHF

Category

Toxic substances.

Toxicity

Grading toxic.

Acute toxicity

Intraperitoneal-rat LD50: 31 mg/kg; subcutaneous-Fox LDL0: 280 mg/kg.

Flammability and hazard characteristics

It release flammable ammonia gas upon thermal decomposition; in case of acid, it releases toxic hydrogen fluoride gas.

Storage characteristics

Treasury: ventilation, low-temperature and drying; store it separately from acids, bases, food and CLF3.

Extinguishing agent

Water

Professional standards

TWA 2.5 mg (fluorine)/cubic meter; STEL 5 mg (fluorine)/cubic meter.

Chemical Properties

Ammonium fluoride,NH4F, is a white crystalline salt that is soluble in cold water. It is unstable and emits a strong odor of ammonia. Ammonium fluoride is used in etching glass,preserving wood,and in the textile industry as a mordant.

Chemical Properties

Ammonium fluoride is a white crystalline solid.

Physical properties

White, deliquescent, crystalline solid; occurs in various forms, as granular powder (commercial products), needles or leaflets, or hexagonal prism (formed on sublimation and condensation); density 1.009 g/cm³ at 25°C; decomposes on heating; highly soluble in cold water (100g/100g at 0°C); decomposes in hot water; slightly soluble in alcohol, insoluble in liquid ammonia.

Uses

It is used for etching of glass, preservation of food, in printing textile, and as mothproofing agent. It is used in chemical analysis and in brewing. It is used in the synthesis of NaHoF4 and NaEuF4, which are important in solid state lasers as well as photoluminescence. The fluoride ion is used as a base and nucleophile in organic synthesis. Ammonium fluoride providee safe deprotection strategy for the tert-butyldimethylsilyl (TBS) group during RNA synthesis.

Uses

Etching and frosting glass; as antiseptic in brewing beer; preserving wood; in printing and dyeing textiles; as mothproofing agent.

Uses

Definition

ChEBI: A fluoride salt having ammonium (NH4+) as the counterion.

General Description

Ammonium fluoride is a white crystalline solid. Ammonium fluoride is soluble in water. Ammonium fluoride is noncombustible. Ammonium fluoride is corrosive to aluminum. Ammonium fluoride is used in chemical analysis, in brewing, and as a preservative for wood.

Air & Water Reactions

Dissolves in water and forms dilute solution of hydrofluoric acid. May corrode glass, cement, and most metals [USCG, 1999]. Water soluble.

Reactivity Profile

Salts, basic, such as Ammonium fluoride, are generally soluble in water. The resulting solutions contain moderate concentrations of hydroxide ions and have pH's greater than 7.0. They react as bases to neutralize acids. These neutralizations generate heat, but less or far less than is generated by neutralization of the bases in reactivity group 10 (Bases) and the neutralization of amines. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible.

Hazard

Corrosive to tissue.

Health Hazard

Inhalation of dust may cause irritation of respiratory system. Ingestion is harmful; readily soluble fluorides may be fatal if relatively small quantities are swallowed. Contact with eyes causes local irritation of the mucous membrane. Contact with skin may cause burns. High concs. of fluorine in the urine have been reported following skin contact.

Safety Profile

Poison by subcutaneous and intraperitoneal routes. See also FLUORIDES. When heated to decomposition it emits very toxic fumes of F-, NO,, and NH3. Incompatible with ClF3

Potential Exposure

Ammonium fluoride is used in printing and dyeing textiles; glass etching, moth-proofing and wood preserving; in analytical chemistry, agriculture, antiseptic in brewing.

Shipping

UN2505 Ammonium fluoride, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Incompatibilities

Acids, alkalis, chlorine trifluoride. Corrodes glass, cement, most metals.

Waste Disposal

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal.