Potash salt beds

Prior to the drilling of the well all geological data, including the seismic was thoroughly reviewed and analyzed. From the data at hand there was no reason to expect an influx of fluid during the second core run in the Prairie Evaporite Formation. Not only is it unusual to encounter fluids in the middle of the salt bed, the pressures encountered in this well are abnormally high for the potash exploration industry. The zero casing and drill pipe pressure was achieved when the fluid column was at 2000 kg/m3. This equates to a bottom-hole pressure of approximately 30 MPa which is hydrostatically over-pressured by about 15 MPa. 

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. 

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). 

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. 

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). 

Manufacture Potassium carbonate (potash) was formerly produced by the ashing of wood and other plant raw materials. Since the middle of the nineteenth century, the saline residues from the rock salt industry and salt deposits have been the raw materials for potassium carbonate production. The currently industrially most important process is the carbonation of electrolytically produced potassium hydroxide. 50% potassium hydroxide solution (e.g. from the mercury process) is saturated with carbon dioxide, the solution partially evaporated and the potassium carbonate hydrate K2CO3 1.5H2O which precipitates out is separated. After drying, the product is either marketed as potash hydrate or is calcined in a rotary tube furnace at temperatures of 250 to 350°C to anhydrous potassium carbonate. Anhydrous potassium carbonate is also produced in a fluidized bed process in which potassium hydroxide is... 

At the Cardona mine, the deposit is formed around a diapiric anticline. The potash beds form a horseshoeshaped deposit 1 km wide and 5 km long around the northern flank of the salt dome. Beds with 20°-80 dips are mined in stopes at depths up to 1,025 m. The potash zone mined varies from 8 to 20 m in thickness and averages 11%-12% K2O. 

In the Silurian Michigan Basin of the United States, potash-bearing salts may occur over an area of 33,800 km, Sylvinite zones with thicknesses up to 27 m and beds containing up to 25% K2O but averaging much less over the potash-bearing interval) have been discovered. A 40,000-tpy KCl solution mining pilot plant has operated on a potash zone at a depth of 1,540-2,560 m for several years. 

Potash minerals The potash deposits have some modes of occurrences which are as marine evaporates, placer deposits etc. K is a constant of such common minerals such as orthoclase feldspar, muscovite, mica etc. While micas are resistant to weathering, orthoclase feldspar becomes decomposed very easily and its potassium content is then carried away in solution by running water and deposited along with bed in sea. Due to evaporation of sea water, large amount of K salts remain as residual product. Orthoclase feldspar... 

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