Nitric
acid, HNO3, is an oily, yellowish liquid, which is a strong acid and
good oxidising agent. Its main use is in getting nitrogen (originally from the
air) into compounds. Nitric acid is made naturally by rain water reacting with
nitrogen oxides in the air. These oxides are made when the high temperatures in
lightning force nitrogen and oxygen to react together.
The process of making nitric acid from ammonia was developed by Friedrich Wilhelm Ostwald at the beginning of the 20th century. This allowed Germany to make explosives during the First World War without relying on the import of nitrates from Chile, which were blockaded by the British navy. The ammonia for the process was made, from nitrogen in the air, by the Haber process, also developed in Germany at about this time.
Ostwald was awarded the Nobel Prize in 1909. Although he did research on ions, for most of his life he refused to believe in the existence of atoms - he saw them as a useful theoretical concept only.
| World production | 60 million tonnes per year |
| UK production | 20 million tonnes per year |
| Manufacture | The Ostwald process |
| Raw material | Ammonia, air, water |
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Making fertilsers (ammonium nitrate) | 85% |
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Making organic nitrogen compounds (eg for plastics and explosives) | 10% |
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Making Nylon | 5% |
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| Map | Aerial view of site |
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| Unlabelled process diagram | Labelled process diagram |
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| Unlabelled diagram of converter | Labelled diagram of converter |
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| Unlabelled diagram of absorption tower | Labelled diagram of absorption tower |
last update March 2006