Potassium fertilizers mineral sources

Nitrogen makes up 78 % of the atmosphere, hence, it is readily available. Ammonia is produced by fixing of atmospheric nitrogen with hydrogen. Mineral sources of phosphorus and potassium are converted to a suitable form for fertilizer. These three elements have other use than fertilizer they are used and interact with other facets of the chemical industry, making a highly complex picture. A schematic of the interactions is presented in Figure 7.2-1. 

Potassium compounds have many similarities to sodium compounds. The principal mineral sources of potassium are carnallite, KCl-MgCl2-6H20, and sylvite, KC1, which is incorporated directly into some fertilizers as a source of essential potassium. Potassium compounds are generally more expensive than the corresponding sodium compounds, but in some applications their advantages outweigh their... 

Some compounds of the s-block elements are important industrial chemicals, too. For example, more than 1.4 billion kilograms of K2 CO3 (potassium carbonate, whose common name is potash), is produced in the United States each year. This compound, which is obtained from mineral deposits, is the most common source of potassium for fertilizers. Fertilization with potassium is necessary because this element is essential for healthy plant growth. Moreover, potassium salts are highly soluble in water, so potassium quickly becomes depleted from the soil. Consequently, agricultural land requires frequent addition of potassium fertilizers. 

Four minerals are the principal commercial sources of potash (Table 2). In all ores, sodium chloride is the principal soluble contaminant. Extraneous water-iasoluble material, eg, clay and siUca, is a significant contaminant ia some of the evaporates being mined from underground deposits. Some European potassium ores contain relatively large amounts of the mineral kieserite, MgS04-H2 0. It is recovered for captive use to produce potassium sulfate compounds or is marketed ia relatively pure form as a water-soluble magnesium fertilizer. 

In the latter half of the nineteenth centuiy the United States was dependent on the vast Stassfurt deposits of Germany for the potassium compounds needed as fertilizers. In 1911 Congress appropriated funds for a search for domestic minerals, salts, brines, and seaweeds suitable for potash production (67). The complex brines of Searles Lake, California, a rich source of potassium chloride, have been worked up scientifically on the basis of phase-rule studies with outstanding success. Oil drillers exploring the Permian Basin for oil became aware of the possibility of discovering potash deposits through chemical analysis of the cores of saline strata. A rich bed of sylvinite, a natural mixture of sylvite (potassium chloride) and halite (sodium chloride), was found at Carlsbad, New Mexico. At the potash plane near Wendover, Utah, the raw material, a brine, is worked up by solar evaporation (67). 

Potassium [7440-09-7], K, is the third element in the alkali metal series. The name designation for the element is derived from potash, a potassium mineral the symbol from the German name kalium, which comes from the Arabic qili, a plant. The ashes of these plants (a/ qih) were the historical source of potash for preparing fertilizers (qv) or gun powder. Potassium ions, essential to plants and animals, play a key role in carbohydrate metabolism in plants. In animals, potassium ions promote glycolysis, lipolysis, tissue respiration, and the synthesis of proteins (qv) and acetylcholine. Potassium ions are also believed to function in regulating blood pressure. 

Potash is any potassium mineral that is used for its potassium content. Most of the potash produced in the United States goes into fertilizer. The major sources of potash are potassium chloride (KCl) and potassium sulfate (K2SO4). Potash production is often reported as the potassium oxide (K2O) equivalent or the amount of K2O that could be made from a given mineral, (a) If KCl costs 0.55 per kg, for what price (dollar per kg) must K2SO4 be sold to supply the same amount of potassium on a per dollar basis (b) What mass (in kg) of K2O contains the same number of moles of K atoms as 1.00 kg of KCl ... 

Sources. The world produces about 30 million tons of potash each year. This is expressed as K2O and includes all primary potassium mineral products. Besides KCl, these include the sulfate and mixed potassium-magnesium sulfates. The major outlet for potash and agricultural fertilizers accounts for about 95% of production. Known... 

Potassium is a relatively abundant element in the earth s crust, ranking seventh in concentration. It is widely distributed geographically and is commonly found in association with sodium compounds. The feldspars, muscovite (white mica), granite, and gneiss are rich sources but because they are siliceous and refractory, they are difficult and costly to convert to forms suitable for use as fertilizers. The common potassium minerals are listed in Table 11.3. 

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