Potassium is the third major plant and crop nutrient after nitrogen and phosphorus. Potash is the common name for various mined and manufactured salts that contain potassium. Today, potash is produced worldwide at amounts exceeding 30 million tons per year. Potassium chloride (KCl) accounts for most of the K used in world agriculture (about 90%). Other widely used K products include potassium sulfate, potassium nitrate, and potassium-magnesium salts.
Potassium bearing minerals are mined from underground ore deposits, salt lakes and brines. Then, the ore must be beneficiated and purified using dry and slurry processes. Guichon Valves can supply custom-made valves suitable for such abrasive slurries.
The majority of mined KCl is used for obtaining various grade fertilizers based on the particle size (granular, standard, fine, soluble). Granular KCl is often applied in mixtures with other N and P based
fertilizers to provide, in one application, the nutrients required by the crops.
Another potassium fertilizer is potassium sulfate, which is frequently used for crops where additional chloride from more common KCl fertilizer is undesirable. Potassium sulfate can be extracted from the mineral langbeinite or it can be synthetized by treating potassium chloride with sulfuric acid at high temperature. By adding magnesium salts to potassium sulfate, a granular potassium-magnesium compound fertilizer can also be produced.