Sodium Nitrate

About This Product

Sodium nitrate has the formula NaNO3 and CAS number 7631-99-4, supplied as white crystals or granules, very soluble in water and mildly hygroscopic. It occurs naturally in the caliche deposits of the Atacama desert, which were the world's principal nitrogen source until the Haber-Bosch process displaced them in the early twentieth century. As a fertiliser it delivers all its nitrogen as nitrate, immediately available and mobile in soil water, with no ammonium fraction to nitrify first. That makes it fast-acting but also readily leached, so it suits situations calling for a rapid correction rather than season-long supply. The sodium it carries is a genuine consideration: on sodic or poorly drained soils sodium accumulation degrades soil structure, and in recirculating hydroponics it builds up to toxicity, so potassium or calcium nitrate is preferred there. Its larger modern market is thermal: mixed with potassium nitrate it forms solar salt, the molten mixture used to store heat in concentrated solar power plants, which remains liquid across a wide temperature range and is stable at high temperature. It is a strong oxidiser. It is used in fertilisers, molten salt thermal storage and heat treatment, glass and ceramic manufacture, meat curing and explosives manufacture. Bio Green Chem supplies sodium nitrate to specification on nitrogen content, chloride, moisture, insolubles, perchlorate and heavy metals.