Ammonium perchlorate ("AP") is an

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemis ...

with the formula NH₄ ClO₄. It is a colorless or white solid that is soluble in water. It is a powerful

oxidizer An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxi ...

. Combined with a fuel, it can be used as a

rocket propellant Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemic ...

called

ammonium perchlorate composite propellant Ammonium perchlorate composite propellant (APCP) is a solid-propellant rocket fuel. It differs from many traditional solid rocket propellants such as black powder or zinc-sulfur, not only in chemical composition and overall performance but als ...

. Its instability has involved it in a number of accidents, such as the

PEPCON disaster On May 4, 1988, a fire followed by several explosions occurred at the Pacific Engineering and Production Company of Nevada (PEPCON) chemical plant in Henderson, Nevada. The disaster caused two fatalities, 372 injuries, and an estimated $100 mill ...

Production

Ammonium perchlorate (AP) is produced by reaction between

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous ...

and

perchloric acid Perchloric acid is a mineral acid with the formula H Cl O4. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid and hydrochloric acid. It is a powerful oxidizer when hot, but aqueo ...

. This process is the main outlet for the industrial production of perchloric acid. The salt also can be produced by

salt metathesis reaction A salt metathesis reaction, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding a ...

of ammonium salts with

sodium perchlorate Sodium perchlorate is the inorganic compound with the chemical formula Na ClO4. It is a white crystalline, hygroscopic solid that is highly soluble in water and in alcohol. It is usually encountered as the monohydrate. The compound is noteworthy ...

. This process exploits the relatively low solubility of NH₄ClO₄, which is about 10% of that for sodium perchlorate.Helmut Vogt, Jan Balej, John E. Bennett, Peter Wintzer, Saeed Akbar Sheikh, Patrizio Gallone "Chlorine Oxides and Chlorine Oxygen Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH. AP crystallises as colorless

rhombohedra In geometry, a rhombohedron (also called a rhombic hexahedron or, inaccurately, a rhomboid) is a three-dimensional figure with six faces which are rhombi. It is a special case of a parallelepiped where all edges are the same length. It can be use ...

Decomposition

Like most ammonium salts, ammonium perchlorate decomposes before

melting Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which in ...

. Mild heating results in production of hydrogen chloride, nitrogen, oxygen, and water. : 4 NH₄ClO₄ → 4 HCl + 2 N₂ + 5 O₂ + 6 H₂O The combustion of AP is quite complex and is widely studied. AP crystals decompose before melting, even though a thin liquid layer has been observed on crystal surfaces during high-pressure combustion processes. Strong heating may lead to

explosion An explosion is a rapid expansion in volume associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Supersonic explosions created by high explosives are known ...

s. Complete reactions leave no residue. Pure crystals cannot sustain a flame below the pressure of 2

MPa MPA or mPa may refer to: Academia Academic degrees * Master of Performing Arts * Master of Professional Accountancy * Master of Public Administration * Master of Public Affairs Schools * Mesa Preparatory Academy * Morgan Park Academy * Mou ...

. AP is a Class 4 oxidizer (can undergo an explosive reaction) for particle sizes over 15 micrometres and is classified as an explosive for particle sizes less than 15 micrometres.

Applications

The primary use of ammonium perchlorate is in making solid fuel propellants."Perchlorate: Overview of Issues, Status, and Remedial Actions"
ITRC, September 2005 When AP is mixed with a fuel (like a powdered aluminium and/or with an

elastomer An elastomer is a polymer with viscoelasticity (i.e. both viscosity and Elasticity (physics), elasticity) and with weak intermolecular forces, generally low Young's modulus and high Deformation (mechanics), failure strain compared with other mate ...

ic binder), it can generate self-sustained combustion at pressures far below atmospheric pressure. It is an important oxidizer with a decades-long history of use in

solid rocket propellant Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical ...

s —

space launch Space launch is the earliest part of a flight that reaches space. Space launch involves liftoff, when a rocket or other space launch vehicle leaves the ground, floating ship or midair aircraft at the start of a flight. Liftoff is of two main ...

(including the

Space Shuttle Solid Rocket Booster The Space Shuttle Solid Rocket Booster (SRB) was the first solid-propellant rocket to be used for primary propulsion on a vehicle used for human spaceflight. A pair of these provided 85% of the Space Shuttle's thrust at liftoff and for the first ...

), military,

amateur An amateur () is generally considered a person who pursues an avocation independent from their source of income. Amateurs and their pursuits are also described as popular, informal, self-taught, user-generated, DIY, and hobbyist. History ...

, and hobby high-power rockets, as well as in some fireworks. Some "breakable" epoxy adhesives contain suspensions of AP. Upon heating to 300 °C, the AP degrades the organic adhesive, breaking the cemented joint.

Toxicity

Perchlorate itself confers little acute toxicity. For example, sodium perchlorate has an of 2-4 g/kg and is eliminated rapidly after ingestion. However, chronic exposure to perchlorates, even in low concentrations, has been shown to cause various

thyroid The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The ...

problems, as it is taken up in place of iodine.

References

https://www.europapress.es/economia/noticia-comunicado-perclorato-amonio-web-ammoniumperchlorateorg-20200304141258.html {{DEFAULTSORT:Ammonium Perchlorate Ammonium compounds Perchlorates Pyrotechnic oxidizers Rocket oxidizers Oxidizing agents Explosive chemicals