Potassium ferrocyanide finds many niche applications in industry. It and the related sodium salt are widely used as anti-caking agents for both road salt and table salt. The potassium and sodium ferrocyanides are also used in the purification of tin and the separation of copper from molybdenum ores. Potassium ferrocyanide is used in the production of wine and citric acid.
In the laboratory, potassium ferrocyanide is used to determine the concentration of potassium permanganate, a compound often used in titrations based on redox reactions. Potassium ferrocyanide is used in a mixture with potassium ferricyanide and phosphate buffered solution (PBS) to provide a buffer for X-Gal, which is used to cleave Beta-galactosidase, giving a bright blue visualization where an antibody (or other molecule), conjugated to Beta-gal, has bonded to its target.
Potassium ferrocyanide can be used as a fertilizer for plants