Also known as saltpeter, potassium nitrate has many uses. The substance is essential for producing gun powder and fireworks. Potassium nitrate also appears as an ingredient in many fertilizers, and food manufacturers often employ potassium nitrate as a food preservative.
In nature, potassium nitrate takes the mineral form of niter, which has the chemical formula KNO3. Niter dissolves easily in water and is most often found as a solid in caves and dried sea beds.
Potassium nitrate serves as the main ingredient in the oldest known form of gun powder, black powder. The explosive and propellant, which the Chinese are credited with inventing sometime between AD 800 and AD 900, contains 75 percent potassium nitrate, 15 percent carbon from charcoal and 10 percent sulfur. Some hunters still use black powder guns. Also, because black powder burns so easily, militaries continue to use the compound for artillery shell primers.
Fireworks, Model Rockets and Artillery
By itself and as a component of black powder, potassium nitrate sees extensive use as a propellant for fireworks and model rockets, according to an entry in the online encyclopedia Chemistrydaily.com.
Fruit and vegetable growers use fertilizers with high potassium nitrate contents because the chemical breaks down quickly and easily into its potassium and nitrogen components in wet soil.
Traditional recipes for smoking and curing meats call for using potassium nitrate as the main preservative. The National Center for Home Food Preservation does caution that too much potassium nitrate can poison diners, however, and advises anyone smoking meats to adhere to federal limits of 2.75 oz. of potassium nitrate per 100 lbs. of meat.