Potassium ferrocyanide appears as tiny light yellow granules. This nonflammable inorganic compound is composed of carbon, nitrogen, iron and potassium in a crystalline structure. It has a melting point of around 70 °C and a boiling point of 400 °C. It is soluble in water but not in ethanol or ether.
It is commonly used as an anti-caking agent for table salts and road salts. It is nontoxic so it poses no harm to the body especially in low concentrations. Even in experiments with rats, a massive dose it required in order to be lethal. However, it should be kept away from potent acids as they mixture could release deadly hydrogen cyanide gas.
This substance is prevalent in the mining industry as it is handy when it comes to isolating metals from impurities. For instance, it is excellent at the removal of copper traces in molybdenum ores. It is also useful when purifying tin.