Sylvinite deposits

Innovative technology has been successfully applied to the preferential solution mining of potassium chloride from the sylvinite deposits 215 m thick and lying some 1600 m below the surface situated under much of southern Saskatchewan. These beds would at best be only marginally profitable to mine by... 

Heavy-Media Separation. Heavy-media separation, depicted in Eigure 3, can only be used for relatively rich sylvinite ores that consist of large crystals of KCl and NaCl, such as those mined in Saskatchewan (6,20). Crystals of the two salts in the Saskatchewan deposits are 6—9 mm in diameter. Mine ore that is cmshed sufficiently to pass through 6—9-mm screens in this size range results in a mixture consisting of discrete grains of each salt. 

Production of KCl at the Wendover, Utah operation employs a large 7000 acre complex of solar ponds. Both shallow brine wells and deeper wells are used to pump brine into the pond complex. In the preconcentration ponds water is evaporated and sodium chloride is crystallized. Later the brine is transferred to production ponds where sylvinite is deposited. Brine is then transferred to other ponds where camaUite is crystallized. Sylvinite is removed from drained ponds with self-loading scrapers and taken to the plant were KCl is separated by flotation with an amine oil collector. The camaUite,... 

Large deposits of sylvinite (42.7% KCl, 56.6% NaCl) near Carlsbad, New Mexico, account for 85% of the potassium products produced in the U.S. The potassium chloride can be separated by either fractional crystallization or flotation. Potassium chloride is also obtained from the brines of Searles Lake, California. All these sources give potash (97% potassium chloride) with a 60% K2O equivalent for fertilizer use. A chemical-grade product can be obtained to a purity of 99.9% potassium chloride. Almost all potash produced is potassium chloride. Potash is used mainly as fertilizer (88%) with a small amount (12%) used in chemical manufacture. 

Potassium chloride is produced by several processes. The salt is recovered from natural brine by solar evaporation in shallow ponds. Various methods are employed in mining ores from their natural deposits. Usually it is recovered from sylvinite or a naturally occuring complex mixture of langbeinite and kainite. 

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). 

Deposits of sylvinite (43% by weight potassium chloride and 57% by weight sodium chloride) account for large amounts of naturally occurring potassium. The potassium chloride can be separated by either fractional crystallization or flotation. Brine is also a valuable source of potassium chloride. A small amount of potassium sulfate is isolated from natural deposits, and potassium nitrate is manufactured by two processes. 

Czechoslovakia has no raw material of this kind so potassium chloride is imported mainly from Stassfurt (where it is prepared from carnallite) and from Alsace (where it is obtained from sylvinite) and Palestine (the Dead-Sea). In the USSR the largest deposits of sylvinite and carnallite are found in the territory between the river Kama and the Ural mountains (Solikamsk). Other potassium salt deposits are at Stebnik near Drogobycz and at Kaluga in West Ukraine. Spain has deposits of sylvinite and carnallite in Catalonia. Deposits... 

Potassium chloride occurs naturally as the mineral sylvite or sylvine it also occurs in other minerals such as sylvinite, camallite, and kainite. Commercially, potassium chloride is obtained by the solar evaporation of brine or by the mining of mineral deposits. 

In the deposits of the Federal Republic of Germany in the Werra-Fulda region so-called hard salts are found (mixtures of potassium chloride, sodium chloride, magnesium sulfate and anhydrite) with camallite seams, which are also found in the Hanover region. Sylvinite, a mixture of sodium and potassium chloride, is also found there. 

Potassium salt deposits are the major raw materiEil source for K fertilizers. These undergound deposits were formed by the evaporation of sea water hence, NaCl is always present as a major contaminant. ME esium salts are also present and these are combined with sulfates md/or chlorides. Potassium chloride (sylvite) is the predominant K form in most deposits, but K also occurs as langbeinite (New Mexico) and as kainite (Sicily) to a limited extent. Some of the langbeinite and virtually all of the kainite is converted to K2SO4 (Barber et al., 1971). However, sylvinite ores are the principal reserves that are economically exploitable and these are judged to be our principal source of K for the next several decades (Adams, 1968). 

Large, deeply buried potash deposits are mainly associated with marine e aporite sequences and less commonly with non-marine evaporites throughout the world. Potash deposits occur on every inhabited continent and have been identified in most geologic time periods from the Cambrian to the present. The most abundant potash mineral in commercial potash deposits is sydvite Sylvite and halite (NaCl) form the common potash ore called sylvinite. In most occurrences, fairly pure sylvinite... 

The Z3 Ronnenberg and Riedel beds consist mainly of sylvinite with sporatic occurrences-of carnallite and-with no magnesium sulfates. Both beds exist as isolated discontinuous units, and occasionally each is minable alone, for example, the Ronnenberg bed at the Zielitz deposit. Here the Ronnenberg bed slopes steadily from 18 to 25 and is found at depths of 400-1,000 m. The bed is 6-9 m thick and contains about 25% KCl (15% K2O), with no sulfates and only minor amounts of insolubles. The halite that overlies the Ronnenberg bed at the Zielitz deposit contains some carnallite. 

Spain - Spain has two exploitable potash areas, occurring at opposite ends of a lor (300 km), narrow depositional basin of Upper Eocene age, formed between the Pyrenes, the Iberian ranges, and the Catalonian coastal range. The saline mineral sequences in both deposits are quite similar, with an old halite at the base, a sylvinite-producing horizon, and carnallite and halite above the main producing horizon. 

The second exploitable area, the Castean or Catalonia potash basin, is located 75 km northwest of Barcelona and covers an area of about 2,600 km. The Catalonia deposit contains 2 to 4 layers of potash ore. The lower sylvinite bed or A bed is typically 3.0-3-2 m thick and averages 18% K2O. Above the A bed is a 2.5-m halite layer, followed by 0.7-0,9 m of sylvinite called the B bed, which analyzes about 35% K2O. Above the B bed are two thin marl layers followed by 6-8 m of alternating carnallite-halite beds. 

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