Annually, SQM produces around 1,5 million MT of nitrates salts from caliche ore and salar brines, two natural resources found in northern Chile. Caliche is mined from surface deposits in the Atacama Desert; derived products include sodium nitrate and iodine. The salar brines are pumped from the underground in the Salar de Atacama (Atacama Salt Flat) after which they are transferred to large solar evaporation ponds to physically separate the desired elements. The main derived products are: lithium chloride, potassium chloride, magnesium chloride, boric acid and potassium sulphate. Nitrates are produced after the caliche mineral is crushed and exposed to a leaching process with water. Sodium nitrate is obtained from this leached solution by crystallization. Part of the obtained sodium nitrate goes through another stage of processing during which it reacts with potassium chloride from the Salar de Atacama. The mixture is then subject to other processes such as crystallization, refining and drying to yield potassium nitrate.
