Niter (redirected from Potash nitre)

niter or nitre: see potassium nitrate.

---

saltpetre

 or nitre also spelled saltpeter or niter

Transparent, colourless, or white powder or crystals of potassium nitrate (KNO₃), found native in deposits. It is a strong oxidizing agent (see oxidation-reduction), used in fireworks, explosives, matches, fertilizers, glassmaking, steel tempering, and food curing; as a reagent; and as an oxidizer in solid rocket propellants. The term is also used for sodium nitrate (Chile saltpetre) and calcium nitrate (lime saltpetre), both of which are used in the nitric acid industry and as fertilizers, and for ammonium nitrate (Norway saltpetre), a high explosive and fertilizer.

---

niter [′nīd·ər]

(inorganic chemistry)

potassium nitrate

---

Niter 

any of-the nitrates (nitric acid salts) of alkali and earth metals and ammonium. In nature, niters are formed during the decomposition of various organic radicals upon the action of nitrifying bacteria. From the mid-14th century, the term “saltpeter” was applied to potassium nitrate (KNO₃)—the main constituent of black gunpowder.

KNO₃ was obtained from niter piles—agglomerates of manure mixed with limestone, marl, and building debris that were placed between layers of brushwood or hay. Decomposition of this mixture yielded ammonia, which, during nitrification (aided by bacteria), was converted first to nitrous and then to nitric acid. Interaction of the nitric acid with CaCo₃ gave Ca(NO₃)₂, which was then leached with water. The addition of wood ash, composed mainly of K₂CO₃, induced the precipitation of CaCO₃ and the formation of a KNO₃ solution. This method was used until 1854, when the German chemist C. Nöllner began producing KNO₃ with the reaction KCl + NaNo₃ = KNO₃ + NaCl in solution. The raw materials here were natural Chile saltpeter (NaNO₃) and KC1, which was obtained from natural potassium salts. This method has gradually replaced the previous one. Niters are primarily used as nitrogenous fertilizers.

S. A. POGODIN