Lithium potassium sulfate from

Great Salt Lake, Utah, is the largest terminal lake in the United States. From its brine, salt, elemental magnesium, magnesium chloride, sodium sulfate, and potassium sulfate ate produced. Other well-known terminal lakes ate Qinghai Lake in China, Tu2 Golu in Turkey, the Caspian Sea and Atal skoje in the states of the former Soviet Union, and Urmia in Iran. There ate thousands of small terminal lakes spread across most countries of the world. Most of these lakes contain sodium chloride, but many contain ions of magnesium, calcium, potassium, boron, lithium, sulfates, carbonates, and nitrates. 

A third source of brine is found underground. Underground brines ate primarily the result of ancient terminal lakes that have dried up and left brine entrained in their salt beds. These deposits may be completely underground or start at the surface. Some of these beds ate hundreds of meters thick. The salt bed at the Salat de Atacama in Chile is over 300 m thick. Its bed is impregnated with brine that is being pumped to solar ponds and serves as feedstock to produce lithium chloride, potassium chloride, and magnesium chloride. Seades Lake in California is a similar ancient terminal lake. Brine from its deposit is processed to recover soda ash, borax, sodium sulfate, potassium chloride, and potassium sulfate. 

Rubidium is recovered from its ore lepidolite or pollucite. Mineral lepidolite is a lithium mica having a composition KRbLi(OH,F)Al2Si30io. The ore is opened by fusion with gypsum (potassium sulfate) or with a mixture of barium sulfate and barium carbonate. The fused mass is extracted with hot water to leach out water-soluble alums of cesium, rubidium, and potassium. The solution is filtered to remove insoluble residues. Alums of alkali metals are separated from solution by fractional crystallization. Solubility of rubidium alum or rubidium aluminum sulfate dodecahydrate, RbAl(S04)2 I2H2O falls between potassium and cesium alum. 

In 1821 Arfwedson published a supplementary note to his lithium research (11), in which he stated that the salt which he had previously reported as lithium acid sulfate must be the normal sulfate and that the double sulfate he had at first taken for lithium alum was really potassium alum resulting from a trace of potassium in his alumina. 

Using a cell that was designed along the lines of a molten carbonate fuel cell (Fig. 22), the removal rates of SOj varied from 78 7o at 600 ppm of SO at the cathode to 24% at 2100 ppm of at the cathode. The same authors [103] also reported an improvement over their earlier study by using a ternary eutectic of lithium, potassium, and sodium sulfates as the electrolyte together with Li20-9Cr03 electrodes, which were found to be stable in the molten electrolyte. 

The original product sold in the United States contains -30% lithium hypochlorite (35% available chlorine), 34% sodium chloride, 20% of potassium and sodium sulfates, 3% lithium chloride, 3% lithium chlorate, 2% lithium hydroxide, 1% lithium carbonate, and the balance is water. It is made from lithium sulfate that is extracted into water from a lithium aluminum silicate ore after it is treated with sulfuric acid. The resulting solution also contains sodium and potassium sulfates. It is neutralized with calcium carbonate to pH 6, treated to remove calcium and magnesium, filtered, and concentrated. Sodium hydroxide is added to convert lithium carbonate to lithium hydroxide. The solution is cooled to 0°C and the resulting sodium carbonate decahydrate crystals are removed by filtration. Slightly more sodium hydroxide than the molar equivalent of lithium hydroxide is then... 

Robinson, R.A. J.M. Wilson R.H. Stokes, "The activity coefficients of lithium, sodium and potassium sulfate and sodium thiosulfate at 25° from isopiestic vapor pressure measurements", JACS, v63, pplOll (1941)... 

The surface tension versus logc functions are plotted for lithium, sodium, potassium, rubidium and cesium decyl sulfate solutions in Fig. 2. While the surface tension curves of the potassium decyl sulfate, rubidium decyl sulfate and cesium decyl sulfate solutions fall into the same group, the surface tension functions of lithium decyl sulfate and sodium decyl sulfate significantly differ from the others. The effect of the counterions on the (j versus logc functions is qualitatively similar to that measured for alkali dodecyl sulfate solutions [9, 10, 11]. 

A new method is proposed for the preparation of surface chemically pure surfactant solutions. Experimental results are presented for the counterion dependence of the adsorption of alkali decyl sulfates at the air/solution interface. The experimental adsorption isotherms calculated from equilibrium surface tension-concentration data show significant counterion dependence. While the adsorption isotherms of potassium decyl sulfate, rubidium decyl sulfate and cesium decyl sulfate fall into the same group, the surface activity of sodium decyl sulfate and lithium decyl sulfate is significantly smaller. The adsorption isotherms do not correspond to the Langmuir isotherm because there is a pronounced change in the shape of the isotherms at around 2-2.5x10 mol/cm surfoce excess. 

Brine can be pumped from the Salar s near-surface salt mass at relative high rates, such as >31.5 liter/sec (500-1000 gpm) without appreciable draw-down, although such high pumping rates would hasten the short-circuiting of brine from nearer the surface and from other areas of the Salar. The brine is saturated with salt, and contains variable concentrations of lithium, potassium, magnesium, sulfate and borate in different locations in the Salar (Tables 1.5 and 1.6 Fig. 1.12). The lithium concentration varies from about 1000-4000 ppm, and averages over 1500 ppm for the two commercial operations on the Salar. The total lithium... 

Lake Zabuye Caka has an especially complex brine, somewhat resembling Searles Lake, but with higher concentrations of all of the alkali metals (K, Li, Rb and Cs Tables 1.10 and 1.12). The lithium content in its brine varies from 500 to 1000 ppm, and the brine has been extensively studied for potential multiple mineral production. The brine is saturated with both salt and potassium sulfate, and during solar evaporation the lithium starts to crystallize at about a two-fold concentration (Table 1.12 Garrett, 1998, 1992). This lake has also been reported as being developed for lithium production (USGS, 2001). 

SQM, as Eoote, initially selected a brine extraction location for its well field where the brine had the maximum potassium and the least sulfate for potash and lithium production, and later a location with the maximum sulfate content for potassium sulfate production (Fig. 1.57). Because of this the plants could initially use the simplest processes and have the lowest capital and operating costs. In the initial operation brine with up to 3400 ppm Li was pumped from the Salar in 40 wells, 28 m deep on a 200-500 m grid, which delivered up to 5280 m /hr of brine to the solar ponds. There were also 13 monitoring wells to follow any changes in the brine concentration and its depth from the surface. The ponds were lined with flexible PVC or reinforced hypalon membranes, and the brine flowed through the sections of the pond system in series. The initial salt ponds had an area of 1.16 million m followed by 3.36 million m for the sylvinite ponds, and later 1 million m of ponds were installed for lithium production. The plant employed 184 people, of which 120 were hired from the sparsely populated local area. Contractors were used to drill and maintain the weUs, harvest the salts, transport them to their respective stockpiles, and reclaim the sylvinite to feed the potash plant s conveyor belt. They also provided all of the miscellaneous trucking needed at the Salar, and transported the potash to Coya Sur or Maria Elena and the concentrated lithium chloride brine to the Salar de Carmen. SQM unloaded the brine and potash, and stacked the later material at its nitrate plants (Harben and Edwards, 1997). 

Pavlovic-Zuvic, P., Parada-Frederick, N., and Vergara-Edwards, L. (1983). Recovery of Potassium Chloride, Potassium Sulfate, Lithium and Boric Acid from the Salar de Atacama. Sixth Symp. Salt 2, 377-394. 

The main metals in brines throughout the world are sodium, magnesium, calcium, and potassium. Other metals, such as lithium and boron, are found in lesser amounts. The main nonmetals ate chloride, sulfate, and carbonate, with nitrate occurring in a few isolated areas. A significant fraction of sodium nitrate and potassium nitrate comes from these isolated deposits. Other nonmetals produced from brine ate bromine and iodine. 

Chemicals from brine, 5 784-803 calcium chloride, 5 793-795 iodine, 5 795—796 lithium, 5 796-797 magnesium compounds, 5 797-798 minerals from brine, 5 790-793 potassium compounds, 5 798-799 recovery process, 5 786-790 sodium carbonate, 5 799-800 sodium chloride, 5 800-801 sodium sulfate, 5 801-802 Chemicals Guideline, integrated,... 

Benzosilole anions have been obtained in three ways, as summarized in Scheme 16. 5-Lithio-5-methyldibenzosilole is thus obtained from bis(di-benzosilole) with lithium in THF, which affords 5,5-dimethyldibenzosilole (54% yield) after trapping by dimethyl sulfate (66). The same species is also formed from 5-methyl-5-(trimethylsilyl)dibenzosilole via the Si-Si bond cleavage on treatment with PhjMeSiLi in THF at -78°C, together with tetramethyldiphenyldisilane (67). The potassium analog can be prepared from the I-hydridobenzosilole by treatment with strong nonnucleo-philic bases such as KH (14). 

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