Potassium mining

During WWI the Germans used LOX (and also liq air explosives) extensively in coal, iron and potassium mines, in tunneling and in... 

Potash Mining Potassium Mining Nitrogen Products Fertilizer Manufacturing... 

Stassfurt deposits Deposits of various salts mined at Stassfurt chiefly for potassium (car-nallite). Kainite, kieserite and gypsum are also present, Bta is obtained as a by-product. 

Certain minerals, however, such as sylvite, carnallite, langbeinite, and polyhalite are found in ancientlake and sea beds and form rather extensive deposits from which potassium and its salts can readily be obtained. Potash is mined in Germany, New Mexico, California, Utah, and elsewhere. Large deposits of potash, found at a depth of some 3000 ft in Saskatchewan, promise to be important in coming years. 

World consumption of potassium salts presentiy exceeds 28 million t of K O equivalent per year. About 93% of that is for fertilizer use (see POTASSIUM compounds). The potash [17353-70-7] industry is essentially a mining and beneftciation industry. The two main fertilizer materials, KCl and K SO are produced by beneftciating ores at the mine sites. The upgraded salts then are shipped to distributors and manufacturers of mixed goods. 

Potassium Chloride. The principal ore encountered in the U.S. and Canadian mines is sylvinite [12174-64-0] a mechanical mixture of KCl and NaCl. Three beneficiation methods used for producing fertilizer grades of KCl ate thermal dissolution, heavy media separation, and flotation (qv). The choice of method depends on factors such as grade and type of ore, local energy sources, amount of clay present, and local fuel and water availabiUty and costs. 

Israel Mining Industries produces potassium nitrate by a process in which KCl is converted to KNO in one step at an ambient temperature ... 

Resources for Potash Fertilizers. Potassium is the seventh most abundant element in the earth s cmst. The raw materials from which postash fertilizer is derived are principally bedded marine evaporite deposits, but other sources include surface and subsurface brines. Both underground and solution mining are used to recover evaporite deposits, and fractional crystallization (qv) is used for the brines. The potassium salts of marine evaporite deposits occur in beds in intervals of haUte [14762-51-7] NaCl, which also contains bedded anhydrite [7778-18-9], CaSO, and clay or shale. The K O content of such deposits varies widely (see Potassium compounds). 

An assessment of world potash resources (108) is shown in Table 15. Of the 67 x 10 t of total estimated reserves and resources in Canada, nearly 5 X 10 t is recoverable by conventional mining methods and the remainder by solution mining. As of 1974, Canada had about half of the known world reserves and about 90% of known world resources of potassium. 

Mine Safety AppHances Company, USA (MSA) developed a reduction process usiag sodium and KCl to produce potassium metal ia the 1950s (4) ... 

Total U.S. production of potassium metal is less than 500 t/yr. There are few commercial producers worldwide, although some companies produce potassium captively. The more prominent producers are CaHery Chemical Company (a division of Mine Safety AppHances Company) in the United States and the People s RepubHc of China. Potassium may be manufactured in Russia as well. Strem Chemicals (U.S.) suppHes small quantities in ampuls. 

Historically, potassium metal was used by the Mine Safety AppHances Company (parent company of Gallery Chemical Company) to develop potassium superoxide [12030-88-5] oxygen source in self-contained breathing equipment (see Oxygen-GENERATION systems). Greater understanding... 

In 1840, potassium was recognized as an essential element for plant growth (6). This discovery and the invention in 1861 of a process to recover potassium chloride from mbbish salt, a waste in German salt mines, started the modem potassium chemical industry (5). Potassium compounds produced throughout the world in 1993 amounted to ca 22 million metric tons as K O equivalent (4), down from ca 24 million t in 1992, having fallen annually from 32 million t in 1989 (2). Estimated production capacity was between 29 and 32 million t in 1992 (2). 

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. 

Further upgrading of the potassium chloride content of the chloride salts recovered from the initial heavy-medium separation takes place in a second heavy-medium separation at a somewhat lower specific gravity than the first separation. Sodium chloride is discarded as a waste the enriched KCl fraction is sent to a flotation process where a final separation of KCl from NaCl is made. Mine-mn ore less than 1 mm that is not amenable to... 

Solvent Extraction. The industrial separation of tantalum from niobium was carried out historicahy by the Marignac process of fractional crystallization of potassium heptafluorotantalate and potassium heptafluoroniobate (15,16) or the long-estabhshed Fansteel process (17), which involved the decomposition of the ore by a caustic fusion procedure. Processors have replaced these expensive processes by procedures based on solvent extraction. This technique was developed in the United States at Ames Laboratory and the U.S. Bureau of Mines (18). Figure 2 shows the flow sheet of an industrial instahation for the hydrometahurgical processing of tantalum—niobium raw materials. 

A fourth source of brine is obtained through solution mining. Potash is mined in Moab, Utah by solution mining. Much of the food-grade sodium chloride in the United States, Europe, and other parts of the world is solution mined. Large beds of potassium salts in Canada and trona beds in Wyoming and California are being solution mined. 

There has been much interest in making chemicals from brine because of the low expense compared to alternative methods. Lithium, for example, had been mostly produced from spodumene ore, but now most is produced from brine. Those now producing from ore are seriously researching brine reserves and contemplating converting to brine sources before the turn of the century. Similady, solar salt has cost advantages over mined rock salt. Potassium chloride produced from brine has more than doubled from 1980 to 1990. 

Potassium cyanide [151 -50-8] KCN, a white crystalline, deUquescent soHd, was initially used as a flux, andlater for electroplating, which is the single greatest use in the 1990s. The demand for potassium cyanide was met by the ferrocyanide process until the latter part of the nineteenth century, when the extraordinary demands of the gold mining industry for alkah cyanide resulted in the development of direct synthesis processes. When cheaper sodium cyanide became available, potassium cyanide was displaced in many uses. With the decline in the use of alkah cyanides for plating the demand for potassium cyanide continues to decline. The total world production in 1990 was estimated at about 4500 t, down from 7300 t in 1976. 

Hot (230-240°F) potassium carbonate treating was patented in Germany in 1904 and perfected into modem commercial requirements by the U.S. Bureau of Mines. The U.S. Bureau of Mines was working on Fischer-Tropsch synthesis gas at the time. Potassium carbonate treating requires high partial pressures of CO2. It therefore cannot successfully treat gas containing only H2S. ... 

Potassium ferf-butoxide was supplied by Mine Safety Appliances (MSA) Research Corporation. 

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