Ammonium hexafluoroaluminate, with the chemical formula (NH4)3AlF6, is a chemical compound composed of ammonium ions (NH4+) and hexafluoroaluminate ions (AlF6^3-). It is also known as ammonium aluminum fluoride.

Ammonium hexafluoroaluminate is a white crystalline powder that is sparingly soluble in water. It has several key properties and uses:

1. Flux in Aluminum Refining: Ammonium hexafluoroaluminate is commonly used as a flux in aluminum refining processes. As a flux, it helps remove impurities and oxides from aluminum during the refining and smelting stages, improving the quality of the final aluminum product.
2. Filler in Welding Rods: It is used as a filler material in welding rods for aluminum and aluminum alloys.
3. Production of Aluminum Alloys: Ammonium hexafluoroaluminate is used in the production of certain aluminum alloys.
4. Catalyst in Organic Synthesis: It can serve as a catalyst in certain organic synthesis reactions.

Ammonium hexafluoroaluminate is considered relatively safe to handle under normal conditions. However, like any chemical compound, it should be handled with care, and proper safety precautions should be followed to avoid unnecessary exposure.

In industrial applications, such as aluminum refining and alloy production, ammonium hexafluoroaluminate plays a crucial role in ensuring the quality and purity of aluminum and its alloys. Its fluxing properties aid in the removal of unwanted impurities, making it an essential chemical in the aluminum industry.