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外観
白色, 結晶～結晶性粉末
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性質
主成分NH4NO3，N ＝ 32～34％．窒素肥料の一つ．無色，斜方晶．－18 ℃ 以下で正方晶，32.1 ℃ で別な斜方晶へ，84.2 ℃ で正方晶，125 ℃ で立方晶へと転移する．密度1.725 g cm－3．硝酸アンモニウムは，アンモニアと硝酸とを常圧または加圧下で中和してつくる．常圧式では45％ 硝酸にアンモニアを加える．中和熱で100～110 ℃ になる硝安液(65％)の一部を中和槽で再使用し，ほかを135 ℃ 以下の温度で蒸発して90％ に濃縮する．加圧式では硝酸の沸点上昇のもとで中和反応を行わせ，中和熱を利用して槽内温度を155 ℃，4 atm に保つ(Fauser式)．防湿に工夫がなされ，油脂で覆ったり，石灰と混合して硝安石灰としたり，硫安(硫酸アンモニウム)を硝安の熱濃厚溶液に加えて硫硝安としている．用途は窒素肥料，爆薬原料など．
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反応
硝酸アンモニウムを開放状態で加熱すると、融点以上で徐々にアンモニアと一酸化二窒素へ分解していきます。触媒として塩化物イオンを用いても、硝酸アンモニウムを分解することが可能です。
また、硝酸アンモニウムを密閉状態で加熱した場合には、容易に爆発反応が起こり、窒素・酸素・水に分解します。ニトロナフタリンや木粉を混ぜたものは、爆発反応を活用した硝安爆薬として使用可能です。
やと同じく、硝酸アンモニウムも水に溶解すると吸熱します。食塩と比べて吸熱反応のエネルギーが大きく、瞬間冷却パックなどの寒剤として用いることも可能です。
参考文献
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溶解性
水に易溶 (214g/100g水 25℃), エタノールに可溶。水に極めて溶けやすく、エタノールにやや溶けやすい。
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解説
硝酸アンモニウムとは、のアンモニウム塩で、無色の結晶です。
別名、硝酸アンモニアや硝安などとも呼ばれます。硝酸アンモニウムは、自然界でも生成されますが、50～70%の硝酸をで中和することによって、大規模製造することが可能です。世界で年間およそ20百万トンの硝酸アンモニウムが生産されています。
これまでに偶然の硝酸アンモニウムの爆発によって、何千人もの人々が命を落としてきました。そのため、多くの国で誤用を懸念して、消費者向けの用途での利用を段階的に廃止しています。
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用途
爆薬原料、殺虫剤
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用途
主たる用途は肥料,火薬原料,硝酸塩原料,ペニシリンの培養,冷却剤、肥料である。
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用途
しょうあんは，肥料や爆薬などの原料として使われる化学合成物質である。硝酸アンモニウムのことで、純粋のものは結晶水のない無色の結晶で、理論的な窒素の含量は35％である。しかし吸湿性が大きいため肥料用硝安には固結防止剤として界面活性剤や選択吸湿剤を添加するので、公定規格ではアンモニア性窒素、硝酸性窒素とも16％以上となっている。硝安は油と混合しただけで爆薬として使われるほど爆発性をもつので有機物との混合については注意が必要で、法的にも危険物の規制を受ける。しかし肥料としては生理的中性の速効性肥料であり硝酸もアンモニウムもともに作物に吸収され、土壌中に悪影響を残さないという環境保全型の優れた特徴がある。ただし、硝酸態窒素を含むので水田には適さず、野菜や果樹などの畑作物に適した肥料である。［小山雄生］『佐々宏一著『火薬工学』（2001・森北出版）』[参照項目] | 硝安爆薬 | 硝酸アンモニウム | 速効性肥料 | 肥料
小学館 日本大百科全書(ニッポニカ) ）
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合成法
工業的に硝酸アンモニウムは、硝酸とアンモニアの酸塩基反応によって得られます。非常に激しい発熱反応です。無水状態のアンモニアを使い、まず硝酸を濃縮します。溶液が形成された後、高濃度の硝酸アンモニウムを残すために、余計な水を蒸発させます。
通常は83%程度で、グレードによっては95%から99.9%の硝酸アンモニウムの溶融物を得ることが可能です。硝酸アンモニウムの溶融物は、スプレータワーでプリルや小さなビーズにするか、回転ドラムで噴霧やタンブリングすることにより顆粒にします。
プリルや顆粒は乾燥と冷却の後に、固結を防止するためにコーティングすることが可能です。
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使用上の注意
吸湿性あり
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説明
Ammonium nitrate is an oxidizer, which may explode under confinement and high temperatures. When mixed with fuel oil, a deflagrating explosive material is created. Ammonium nitrate and fuel oil were used as the explosive in the Alfred P. Murrah Federal Building terrorist attack in Oklahoma City and the first terror attack on the World Trade Center in New York City in the mid-1990s.
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化学的特性
Ammonium nitrate,NH4N03, is a colorless crystalline solid existing in two forms, Between 16 and 32°C, the crystals are tetragonal; between 32 and 84 DC, the crystals are rhombic. The melting point of NH4N03 is 169.6 DC, and it decomposes above 210°C. When heated, ammonium nitrate yields nitrous oxide gas. Ammonium nitrate is soluble in water, in acetic acid solutions containing ammonia, is slightly soluble in ethanol, and is moderately soluble in methanol.
Ammonium nitrate is a very insensitive and stable high explosive used as a slow-burning propellant for rockets when compounded with burning rate catalysts. Although the major applications of Ammonium nitrate are explosives and fertilizers, it is also used in insecticides, rust inhibitors, and pyrotechnics.
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使用
Ammonium nitrate (NH4NO3, also known as “Norway saltpeter”) is mainly used as a fertilizer.
It is also known as the chemical that was mixed with diesel fuel to create the explosion
that demolished the Murrah Federal Building in Oklahoma City in 1995.
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定義
ammonium nitrate: A colourlesscrystalline solid, NH4NO3; r.d. 1.72;m.p. 169.6°C; b.p. 210°C. It is verysoluble in water and soluble inethanol. The crystals are rhombicwhen obtained below 32°C andmonoclinic above 32°C. It may bereadily prepared in the laboratory bythe reaction of nitric acid with aqueousammonia. Industrially, it is manufacturedby the same reaction usingammonia gas. Vast quantities of ammoniumnitrate are used as fertilizers(over 20 million tonnes per year)and it is also a component of someexplosives.
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一般的な説明
A colorless crystalline solid. Soluble in water. Does not readily burn but will do so if contaminated with combustible material. Accelerates the burning of combustible material. Produces toxic oxides of nitrogen during combustion. Used to make fertilizers and explosives, and as a nutrient in producing antibiotics and yeast.
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空気と水の反応
Water soluble. Hot aqueous solutions of the nitrate above 50% conc., under confinement may decompose explosively. This process is aided catalytically with such substances as nitric acid and chloride ion, [Chem. Abs., 1982, 97, 78074].
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反応プロフィール
The hazards of AMMONIUM NITRATE have been well studied because of several extremely severe explosions [Chem. Eng., 1962, 70, 91; Bretherick, 5th Ed., 1995]. Mixtures with alkyl esters may explode, owing to the formation of alkyl nitrates. Mixtures with phosphorus, tin(II) chloride or other reducing agents may react explosively [Bretherick 1979 p. 108-109]. A mixture with aluminum powder (also zinc, cadmium, copper, magnesium, lead, cobalt, nickel, bismuth, chromium, and antimony) can be used as an explosive. A number of explosions in which ammonium nitrate and aluminum were mixed with carbon or hydrocarbons, with or without oxidizing agents have occurred [Mellor 5:219 1946-47]. A mixture with acetic acid ignites when warmed, especially if concentrated [Von Schwartz p. 322 1918]. Causes the decomposition of sodium hypochlorite within a few seconds [Mellor 2 Supp. 1:550 1956].
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危険性
May explode under confinement and high temperatures, but not readily detonated. Ventilate well. To fight fire, use large amounts of water. The material must be kept as cool as possible and removed from confinement and flooded with water in event of fire.
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健康ハザード
Inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns or death. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause pollution.
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火災危険
These substances will accelerate burning when involved in a fire. Some may decompose explosively when heated or involved in a fire. May explode from heat or contamination. Some will react explosively with hydrocarbons (fuels). May ignite combustibles (wood, paper, oil, clothing, etc.). Containers may explode when heated. Runoff may create fire or explosion hazard.
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使用用途
硝酸アンモニウムは、主に肥料として使用されることが多い物質です。ただし、硝酸アンモニウムの肥料は、水によって脱窒しやすいため、水田には不向きとされています。
その他の用途として、火薬や花火製造、除草剤、殺虫剤、寒剤、酵母培養の養分、麻酔薬の製造、マッチの製造原料、ロケットエンジンの推進剤などが挙げられます。さらに、爆薬としても利用可能です。特に94%の硝酸アンモニウムと6%の燃料油を混合したANFO爆薬が有名で、採石場・セメント産業・石炭採掘用などで使用されています。
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職業ばく露
Used in the manufacture of liquid and
solid fertilizer compositions, industrial explosives and
blasting agents from ammonium nitrate, matches; antibiotics;
in the production of nitrous oxide.
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代謝
Ammonium Nitrate. Ammonium nitrate is one of the
two leading nitrogen fertilizer materials on a world basis:
10% in 1997. The high N content is advantageous for the
reduction of freight and application costs per unit weight
of nitrogen. The presence of 50% of the nitrogen in the
highly available nitrate form makes it suitable for use
in regions growing crops with a short vegetation period
but has the disadvantage that, because the NO3
? ion is
not adsorbed by soil, it may contribute to relatively large
nitrogen losses by the leaching of increased soil nitrate
into streams and groundwater. Although the application
of any nitrogenous fertilizer results in some degree of soil
acidification, the nitrate form is notably less acidifying
than ammonium sulfate and has a lower tendency for the
loss of nitrogen to the atmosphere as gaseous ammonia.
The hygroscopic character of the crystalline material,
coupled with its explosive nature, contributes to difficult
storage and handling properties and the need for the
production of purified and stabilized forms.
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輸送方法
Ammonium nitrate with organic coating:
UN0222 Ammonium nitrate, with . 0.2% combustible
substances, including any organic substance calculated as
carbon, to the exclusion of any other added substance,
Hazard Class: 1D; Labels:1D-Explosive (with a mass
explosion hazard); D-Substances or articles which may mass detonate (with blast and/or fragment hazard) when
exposed to fire. Ammonium nitrate with NO organic coating:
UN1942 Ammonium nitrate, with NOT . 0.2% of
combustible substances, including any organic substance
calculated as carbon, to the exclusion of any other added
substance (also used for fertilizer), Hazard Class: 5.1;
Labels: 5.1-Oxidizer. UN3375 Ammonium nitrate emulsion
or Ammonium nitrate suspension or Ammonium
nitrate gel, intermediate for blasting explosives, Hazard
Class: 5.1; Labels: 5.1-Oxidizer. UN2072 Ammonium
nitrate fertilizer, n.o.s., doesn’t appear in the 49 CFR
Hazmat Table, refer to UN1942, above). UN2071
Ammonium nitrate based fertilizer, Hazard class: 9;
Labels: 9-Miscellaneous hazardous material. UN2426/140
Ammonium nitrate, liquid (hot concentrated solution),
Hazard Class: 5.1; Labels: 5.1-Oxidizer.
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純化方法
It is crystallised twice from distilled water (1mL/g) by adding EtOH, or from warm water (0.5mL/g) by cooling in an ice-salt bath. Dry it in air, then under vacuum. After 3 recrystallisations of ACS grade, it contained Li and B at 0.03 and 0.74 ppm, respectively. It is deliquescent. [Early & Lowry J Chem Soc 115 1387 1919, 121 963 1922, Hendricks et al. J Am Chem Soc 54 2766 1932.]
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不和合性
A strong oxidizer. Reducing agents;
combustible materials; organic materials; finely divided
(powdered) metals may form explosive mixtures or cause
fire and explosions. When contaminated with oil, charcoal
or flammable liquids, can be considered an explosive which
can be detonated by combustion or shock.
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廃棄物の処理
Pretreatment involves addition
of sodium hydroxide to liberate ammonia and form the
soluble sodium salt. The liberated ammonia can be recovered
and sold. After dilution to the permitted provisional
limit, the sodium salt can be discharged into a stream or
sewer.
