Searles Lake brine

Teeple, J. E., "The Industrial Development of Searles Lake Brines. American Chemical Society, Washington, D.C. 1929. 

Searles Lake brine. See brine Trona process. 

Derivation Fractional crystallization from Searles Lake brine, solution of kernite ore followed by crystallization. Also from colemanite, natural borax, ux-elite, and other borates. 

Derivation Crystallization of a solution containing equimolar quantities of sodium carbonate and sodium bicarbonate, also occurs native (as trona) in desert areas and in Searles Lake brine. 

Trona concentrate is not technically classified as a mineral, but is rather the by-product of potassium and borax recovery from Searles Lake brine in California. The concentration of lithium in this brine is low (approximately 0.03% LiCl), and it would be uneconomical to process this brine for lithium values alone. The name Trona comes from the mixed crystal NaHCOs. Na2C03.2H2O, which is one of the products of Searles Lake. 

Teeple, J.E. (1929) The Industrial Development of Searles Lake Brines, Chemical Catalog Co, New York. 

Precipitating lithium from low-lithium brines with sodium phosphate has also been tested, after the model of licons being precipitated from Searles Lake brine. Tandy and Canfy (1993) smdied the precipitation of lithium phosphate from Dead Sea potash pond end-liquor, and found that perhaps a 70% Li recovery could be obtained. By adding over a 30-fold molar excess of disodium phosphate to the lithium in the brine, adjusting the pH to 6-7, heating to 80°C, and with a 20-30 min residence time about 76% of the lithium would be precipitated along with dicalcium phosphate and the excess disodium phosphate. The precipitate contained about 0.3% Li, and could be leached with water to recover over 90% of the Li, with the remainder being in the residual phosphate precipitate. The filtrate contained about 1440 ppm Li in a sodium phosphate-chloride solution (Table 1.34). 

Smith, G. I. (1976). Origin of Lithium in Searles Lake Brines. U.S. Geol Survey Prof. Paper 1005, 92-103. 

Lithium is presently being recovered from brines of Searles Lake, in California, and from those in Nevada. Large deposits of quadramene are found in North Carolina. The metal is produced electrolytically from the fused chloride. Lithium is silvery in appearance, much like Na and K, other members of the alkali metal series. It reacts with water, but not as vigorously as sodium. Lithium imparts a beautiful crimson color to a flame, but when the metal burns strongly, the flame is a dazzling white. 

The element is much more abundant than was thought several years ago. It is now considered to be the 16th most abundant element in the earth s crust. Rubidium occurs in pollucite, leucite, and zinnwaldite, which contains traces up to 1%, in the form of the oxide. It is found in lepidolite to the extent of about 1.5%, and is recovered commercially from this source. Potassium minerals, such as those found at Searles Lake, California, and potassium chloride recovered from the brines in Michigan also contain the element and are commercial sources. It is also found along with cesium in the extensive deposits of pollucite at Bernic Lake, Manitoba. 

Table 11. Brine Analyses from Searles Lake...

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. 

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). 

A unique liquid—liquid extraction process for manufacturing boric acid from sodium borate brines has been operated at Searles Lake, Trona, California, by the North American Chemical Co. since 1962. Both potassium sulfate and sodium sulfate are produced as coproducts in this process. 

Potassium does not occur in nature in tlie free state because of its great chemical reactivity. The major basic potash chemical used as a source of potassium is potassium chloride, KC1. The potassium content of all potash sources generally is given in terms of the oxide K2O. The majority of potash produced comes from mineral deposits that were formed by llie evaporation of prehistoric lakes and seas which had become enriched in potassium salts leached from the soil, In addition ro natural deposits of potassium salts, large concentrations of potassium also are found in some bodies of water, including the Great Salt Lake and the Salduro Marsh in Utah, the Dead Sea between Israel and Jordan, and Searles Lake in California. All of these brines are used for the commercial production of potash. 

Sulfate of potash (K2S04), unlike the earlier-discussed potash salts, does not occur as natural deposits. It can be recovered by fractional crystallization from such natural brines as those of the Great Salt Lake in Utah and Searles Lake in California. Here separation and recovery are achieved by solar evaporation in shallow ponds. These processes can be utilized only where a suitable brine source is available, and where solar evaporation rates are high. 

Relatively small quantities of soda ash are produced from alkaline brines at Searles Lake, California, by a process of fractional crystallization that also produces other sodium and potassium salts. Table 26.4 shows the current distribution of soda ash uses in the United States. Over the past several years, the totals have changed relatively little. 

In the United States, the brine in Searles Lake, CA contains about 450 million tons of sodium sulfate, or about 35 percent of the... 

A similar process is practiced at Searles Lake. There the brine is first carbonated and chilled to remove sodium carbonate and borax. Further chilling crystallizes Na2S04 as the hydrate, Glauber s salt, and some remaining borax. The coarse crystals of Glauber s salt are separated from the fine crystals of borax in a hydraulic classifier. The sulfate fraction is then filtered, washed, dried, and evaporated to produce anhydrous Na2S04. 

Sodium carbonate bearing deposits and brines exist around die world. Locations are known in die United States, China, Turkey, Bolivia, Brazil, Venezuela, Mexico, India, Pakistan, USSR, Kenya, Australia, and Botswana (14—20). The overwhelming majority of natural ash production comes from die Green River Basin in southwestern Wyoming. Significant amounts are also produced at Searles Lake in California lesser amounts at Lake Magadi in Kenya. Minor quantities are reportedly produced in Pakistan, die USSR, and China and small amounts of impure trona come from Owens Lake, California. A plant is currently under construction to recover soda ash from brine at Sua Pan, Botswana. Each deposit has its own distinctive characteristics and each requires different processing techniques. 

Searles Lake. Searles Lake is a large evaporite deposit about 78 km square and 46 rn deep. It contains a complex mixed salt system that includes trona along with potassium, boron, and other salts (23,24). North American Chemical Company recovers soda ash (1.0 x 10° t/yr) from the lake by carbonating and cooling the brine to crystallize sodium bicarbonate (25). The bicarbonate is filtered and calcined to light soda ash which is densified by conversion to the monohydrate followed by calcining. The procedure results in a dense ash with properties equivalent to Wyoming trona derived ash. 

Sua Pan, Botswana. A soda asli plant is under construction at Sua Pan in Botswana (32). The plant will recover ash from an alkali brine via a process similar to that at Searles Lake (29). 

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