Sodium nitrate was used extensively as
> a fertilizer and a raw material for the manufacture of gunpowder
> It can be combined with iron hydroxide to make a resin.
> can be used in the production of nitric acid by combining it with sulfuric acid and subsequent separation through fractional distillation of the nitric acid, leaving behind a residue of sodium bisulfate.
> Hobbyist gold refiners use sodium nitrate to make a hybrid aqua regia that dissolves gold and other metals.
> Sodium nitrate is also a food additive used as a preservative and color fixative in cured meats and poultry;
Sodium nitrate should not be confused with sodium nitrite, which is also a common food additive and preservative used for example, in deli meats.
> Less common applications include as an oxidizer in fireworks replacing potassium nitrate commonly found in black powder and as a component in instant cold packs.
> Sodium nitrate is used together with potassium nitrate and calcium nitrate for heat storage and, more recently, for heat transfer in solar power plants.
A mixture of sodium nitrate, calcium nitrate and potassium nitrate is used as energy storage material in prototype plants, such as Andasol Solar Power Station and the Archimede project.
It is also used in the wastewater industry for facultative microorganism respiration. Nitrosomonas, a genus of microorganisms, consumes nitrate in preference to oxygen, enabling it to grow more rapidly in the wastewater to be treated.