Potash

Potash (/ˈpɒtæʃ/) includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, which refers to plant ashes soaked in water in a pot, the primary means of manufacturing the product before the industrial era. The word potassium is derived from potash.Potash refers to potassium compounds and potassium-bearing materials, the most common being potassium chloride (KCl). The term potash comes from the Middle Dutch word potaschen (pot ashes, 1477).The old method of making potassium carbonate (K2CO3) was by collecting or producing wood ash (an occupation carried out by ash burners), leaching the ashes and then evaporating the resulting solution in large iron pots, leaving a white residue called pot ash. Approximately 10% by weight of common wood ash can be recovered as pot ash. Later, potash became the term widely applied to naturally occurring potassium salts and the commercial product derived from them.All commercial potash deposits come originally from evaporite deposits and are often buried deep below the earth's surface. Potash ores are typically rich in potassium chloride (KCl), sodium chloride (NaCl) and other salts and clays, and are typically obtained by conventional shaft mining with the extracted ore ground into a powder. Other methods include dissolution mining and evaporation methods from brines.Excessive respiratory disease has been a concern for potash miners throughout history due to environmental hazards, such as radon and asbestos. Potash miners are liable to develop silicosis. Based on a study done between 1977 and 1987, cardiovascular disease among potash workers, the overall mortality rates were low, but a noticeable difference in above-ground workers was documented.Potash (especially potassium carbonate) has been used in bleaching textiles, making glass, and making soap, since about AD 500. Potash was principally obtained by leaching the ashes of land and sea plants. Beginning in the 14th century potash was mined in Ethiopia. One of the world's largest deposits, 140 to 150 million tons, is located in the Tigray's Dallol area. Potash was one of the most important industrial chemicals. It was refined from the ashes of broadleaved trees and produced primarily in the forested areas of Europe, Russia, and North America. The first U.S. patent of any kind was issued in 1790 to Samuel Hopkins for an improvement 'in the making of Pot ash and Pearl ash by a new Apparatus and Process'. Pearl ash was a purer quality made by calcination of potash in a reverberatory furnace or kiln. Potash pits were once used in England to produce potash that was used in making soap for the preparation of wool for yarn production.Potassium is the third major plant and crop nutrient after nitrogen and phosphorus. It has been used since antiquity as a soil fertilizer (about 90% of current use). Elemental potassium does not occur in nature because it reacts violently with water. As part of various compounds, potassium makes up about 2.6% of the Earth's crust by mass and is the seventh most abundant element, similar in abundance to sodium at approximately 1.8% of the crust. Potash is important for agriculture because it improves water retention, yield, nutrient value, taste, color, texture and disease resistance of food crops. It has wide application to fruit and vegetables, rice, wheat and other grains, sugar, corn, soybeans, palm oil and cotton, all of which benefit from the nutrient’s quality-enhancing properties.