KCl

Potassium chloride (KCl) is an inorganic compound composed of potassium ions (K+) and chloride ions (Cl−). It occurs as a white, odorless crystalline solid. The natural mineral form sylvite is a major source, while industrial KCl is produced from potash ore or by reacting potassium hydroxide with hydrochloric acid. Its molar mass is 74.55 g/mol.

KCl crystallizes in a cubic lattice and has a melting point of about 770°C and a boiling point near 1,410°C. It is highly soluble in water, with a solubility of roughly 34 grams per 100 grams of water at 20°C. It is nonflammable and forms a transparent, colorless solution when dissolved.

Occurrence and production: KCl occurs in evaporite potash deposits mined for fertilizer production. Refined KCl grades are used for agricultural, pharmaceutical, and food applications. Industrially, it can be produced by crystallizing from potassium-containing brines or by chemical reactions such as neutralizing potassium hydroxide with hydrochloric acid, followed by purification and crystallization.

Uses: The largest use of KCl is as a fertilizer, supplying potassium in NPK blends. It is also used as a dietary potassium supplement and as a salt substitute in reduced-sodium foods. Additional applications include electrolyte replenishment in medicine, de-icing of roads in some regions, and various industrial processes such as glassmaking and chemical synthesis.

Safety and environmental considerations: KCl is relatively stable and of low volatility, but excessive potassium intake can affect heart and kidney function, so dietary use is regulated. Mining and processing of potash ore can have environmental impacts, including water use and habitat disruption, so responsible management is important.