Page 21 - Curriculum Visions Dynamic Book

Nitrate-containing rocks
Rocks containing nitrogen
are uncommon. They consist mainly of a rock called saltpetre (potassium nitrate), the
largest source of which is in
the deserts of Chile. Because natural supplies of nitrates
are so scarce, and the need
for fertilisers so important, countries are reluctant to be dependent on such overseas sources. As a result, the Haber–Bosch process of using ammonia (see page 16) has been adopted throughout the world.
 The majority of ammonium nitrate is produced from ammonia using the Haber–Bosch process.
 Potassium nitrate occurs naturally as the mineral saltpetre, which is found in abundance in Chile and in much smaller deposits as a white crust in rocks and caves.
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