potash - Potash production and trade

Potassium oxide, K₂O. The term is generally used for any potassium compounds used as fertilizers whose potassium content is reported in terms of the equivalent amount of K₂O, or about 1·2 times the percentage by weight of potassium.

Potash (or carbonate of potash) is an impure form of potassium carbonate (K2CO3) mixed with other potassium salts.

The term has become somewhat ambiguous due to the substitution in fertilizers of cheaper potassium salts, such as potassium chloride (KCl) or potassium oxide (K2O), to which the same common name is now sometimes also applied.

The element potassium derives its English name from potash. A number of chemical compounds containing potassium use the word potash in their traditional names:

potash fertilizer	potassium oxide,	K2O
caustic potash or potash lye	potassium hydroxide,	KOH
carbonate of potash, salts of tartar, or pearlash	potassium carbonate,	K2CO3
chlorate of potash	potassium chlorate,	KClO3
muriate of potash	potassium chloride,	KCl
nitrate of potash or saltpeter	potassium nitrate,	KNO3
sulfate of potash	potassium sulfate,	K2SO4

Potash production and trade

Up until the 20th century, potash was one of the most important industrial chemicals in Europe.

Potash production provided late 18th and early 19th century settlers in North America a way to obtain badly needed cash and credit while they were in the process of clearing their wooded land for crops. Potash was so important at the time that the first patent issued in the United States on July 31, 1790 was on the subject of making of potash.

If desired, the potash could be further refined by baking in a kiln to produce a less impure form of potassium carbonate, known as pearlash for its pearly white color.

The world's largest potash producer is the Potash Corporation of Saskatchewan. The main producers are North America (mainly Saskatchewan, with two-thirds of the world's recoverable potash located there), Russia, Belarus, Germany, Israel and Jordan, (the later two both using solar evaporation pans at the Dead Sea to produce carnallite from which potassium chloride is produced).