Sodium nitrate (Chile saltpeter)

Chemical formula: NaNO₂

CAS: 7631-99-4

Description:
This substance appears as white crystalline granules, occasionally exhibiting faint yellow or greenish hues. It is characterized by a distinctly sharp, bitter-salty flavor. The compound demonstrates high solubility across a range of solvents, including water, ethanol, methanol, and liquid ammonia, which broadens its utility in diverse industrial processes.
Commercially, it is produced in two specialized grades tailored to end-use requirements:
  • Grade A: Designed for high-purity applications such as metal soldering operations, flux formulation, pyrotechnic manufacturing, and the production of premium glass products—including crystal ware and optical lenses.
  • Grade B: Optimized for industrial surface treatments like metal etching, as well as for recycling processes involving tungsten-containing waste streams and other metallurgical recovery operations.

Key Uses:
Sodium nitrate is most widely recognized as a fast-acting nitrogen fertilizer, applied to enrich soil prior to planting and to support plant nutrition throughout the growing season. Beyond agriculture, it serves as a functional component in numerous technical formulations:
  • Metalworking fluids and salt-based lubricants employed in the acid pickling and cold rolling of stainless steel tubing;
  • Glass manufacturing additives that facilitate decolorization and improve optical clarity during melt processing;
  • Heat-treatment media, particularly as a constituent of quenching baths used to harden metals in metallurgical operations;
  • Energetic materials, including solid propellants for rocketry and various pyrotechnic mixtures requiring controlled oxidation;
  • Industrial refrigeration systems, where aqueous salt solutions act as efficient, low-temperature heat-transfer fluids.