Ammonium acid fluoride what is the main use

Ammonium fluoride has three main uses. First, in the field of metallurgy, it is often used as a melting aid. When covering metallurgy, the melting point of materials is quite high, and processing is not easy. Ammonium fluoride can reduce its melting point, making metals easy to melt and purify, just like it can turn hard ice into soft water, making metal smelting smoother. Second, it is also indispensable in the art of glass etching. The surface of glass is hard and smooth, and it is not easy to engrave exquisite patterns or words. Ammonium fluoride can react with silica in glass to etch the desired shape, just like a craftsman's careful carving with a knife, giving glass a different beauty. Third, it is an important reagent in the process of chemical analysis. When analyzing the composition of various substances, ammonium acid fluoride can react uniquely with specific elements or compounds. Through such reactions, the composition and content of substances can be accurately determined, which is like a discerning eye.

Ammonium acid fluoride physical and chemical properties

Ammonium acid fluoride, that is, ammonium hydrogen fluoride ($NH_4HF_2 $), has the following physical and chemical properties:

In terms of view, ammonium hydrogen fluoride is a colorless crystal, like fine particles, often in the state of lumps or powders. Its smell has a sour odor.

In terms of solubility, it is easily soluble in water and dissociated in water, and its aqueous solution is acidic. And soluble in alcohols, but insoluble in acetone.

The melting point is about 125.6 ° C. When heated to the melting point, it melts into a liquid state. When it reaches 240 ° C, it will decompose to produce gases such as hydrogen fluoride.

Ammonium hydrogen fluoride is highly corrosive, can erode silicon-containing substances such as glass, and can also react chemically with metals. Because it can react with many substances, it is often used as an etchant in chemical production, used in the glass industry to etch glass and shape exquisite patterns; in the metal surface treatment process, the oxide on the metal surface is removed to make the metal surface cleaner and easier for subsequent processing.

In addition, because it contains ammonium ions and fluoride ions, in the agricultural field, after reasonable deployment, it can be used as a fluorine-containing trace element fertilizer to supplement plants with fluorine elements. However, when using, it needs to be handled with caution, because it is corrosive and toxic. If not handled properly, it will endanger personal safety and the environment.

Ammonium acid fluoride in storage and transportation

Ammonium acid fluoride has a wide range of properties and is widely used. It should not be careless in storage and transportation.

Its storage is also the first choice for heavy storage. It should be made of corrosion-resistant materials, such as plastics, specific alloy containers, etc. Because of its acid nature, it is easy to react with metals, causing damage and leakage, endangering the surroundings. The storage place should be cool, dry and well ventilated, protected from direct sunlight, so as not to decompose or accelerate the reaction due to heat. And when it is far away from fire and heat sources, fire protection is not possible.

Also, ammonium acid fluoride should be stored separately from other substances. Do not mix with alkalis, oxidants, etc. Alkali and acid fluoride will react violently when encountered; oxidizing agents may also promote their decomposition, which can cause danger.

As for transportation, the carrier must ensure that it is airtight and firm. When loading and unloading, be careful to handle it with care. It is forbidden to drop, heavy pressure, and prevent package damage. During transportation, keep cool and ventilated, and avoid high temperature and hot topics. If it involves long distances, it is even more necessary to check the condition of the carrier and the goods to ensure their safety.

The escort must be familiar with its nature and emergency methods. In case of leakage, etc., it should be handled according to the plan as soon as possible to ensure the safety of the environment and people. Overall, the storage and transportation of ammonium acid fluoride is related to safety and effectiveness, and all details require careful attention.

Ammonium acid fluoride production method

Ammonium fluoride, the method of making it, has its own technique in ancient times. It is often obtained by combining hydrofluoric acid with ammonia gas. Prepare hydrofluoric acid first, which has strong corrosive properties and must be used with care. Take a pottery urn or a lead kettle as a vessel and put hydrofluoric acid in it. Next, let ammonia gas slowly enter it. Ammonia gas enters the acid, like fog into the abyss, and the two are phased, and then form ammonium acid fluoride.

The reason for its transformation is that the fluoride ion in hydrofluoric acid is combined with the ammonium ion in ammonia water. Ammonia is a colorless and irritating gas, easily soluble in water to form ammonia water. Hydrofluoric acid also has a strong pungent taste and strong sex. The two meet, calm down in the vessel, and when it is completed, a liquid of ammonium acid fluorine can be obtained. < Br >
Repeat the liquid with a slow fire to steam it, so that the water gradually goes away, and the ammonium acid fluorine gradually thickens. The fire should not be fierce, lest its quality change. Until the liquid is thick, move to a cool place, and wait for it to crystallize. When the crystals come out, it is the finished product of ammonium acid fluoride.

There is also another way, using calcium fluoride and sulfuric acid to heat together to obtain hydrofluoric acid gas, which can be introduced into ammonia water, and can also form ammonium acid fluoride. However, the combination of calcium fluoride and sulfuric acid requires high temperature, and sulfuric acid is also very corrosive. During operation, regulations must be strictly observed to prevent accidents. Although the method of making ammonium acid fluoride is different, it is all serious and strict. It is related to people and property and cannot be ignored.

Ammonium acid fluoride on the environment and human impact

Ammonium fluoride, that is, ammonium hydrogen fluoride ($NH_ {4} HF_ {2} $), has many effects on the environment and the human body.

In terms of the environment, if it flows into the water body, it will cause water quality to deteriorate. Ammonium hydrogen fluoride can dissociate fluoride ions in water. Fluoride ions are highly active and can complex with various metal ions in water, changing the chemical properties of the water body. Aquatic organisms are extremely sensitive to fluoride ions. Even at low concentrations of fluoride ions, long-term effects will affect their growth, reproduction, and even death, destroying the aquatic ecological balance. When fluoride ions flow into the soil, they will be adsorbed by soil particles, changing soil physicochemical properties, reducing soil fertility, affecting plant root absorption of nutrients, and hindering plant growth. And the volatile gas produced by it will pollute the air and cause adverse effects on the surrounding atmospheric environment.

As far as personal effects are concerned, ammonium hydrofluoride is corrosive. If it comes into contact with the skin carelessly, it will cause intense tingling and burns. In mild cases, erythema and blisters will appear, and in severe cases, tissue necrosis will leave scars. Contact with the eyes is even more harmful, and it can cause damage to the conjunctiva and cornea, and blindness in severe cases. If inhaled, its volatile gas will irritate the respiratory tract, causing symptoms such as cough, asthma, and breathing difficulties. Long-term inhalation may damage the lungs and cause chronic respiratory diseases. Accidentally ingesting ammonium hydrofluoride can burn the digestive tract, cause vomiting, abdominal pain, diarrhea, etc., and in severe cases, it will endanger life. Therefore, when using and handling ammonium hydrogen fluoride, it is necessary to strictly follow safety procedures and take protective measures to prevent damage to the environment and people.