Lithium carbonate, solution preparation

Large lithium reserves are available in South America. A resource of special interest is the dried up salt lake Atacama, 2500 m above sea level in northern Chile. The main component is halite, rock salt, NaCl. In cavities a concentrated salt solution is present, in which the lithium content is as high as 0.15%. This solution is transported to nearby Antofagasta. In a chemical factory there the lithium carbonate is prepared from the chloride. This carbonate is an important export product. Lithium-containing brines are also available in Nevada in the USA. The brines are pumped from the ground through a series of open dams. Through solar evaporation over 12 to 18 months the brine increases its lithium concentration to about 0.6%. Soda is added and lithium carbonate precipitates. 

Lithium Iodide. Lithium iodide [10377-51 -2/, Lil, is the most difficult lithium halide to prepare and has few appHcations. Aqueous solutions of the salt can be prepared by carehil neutralization of hydroiodic acid with lithium carbonate or lithium hydroxide. Concentration of the aqueous solution leads successively to the trihydrate [7790-22-9] dihydrate [17023-25-5] and monohydrate [17023-24 ] which melt congmendy at 75, 79, and 130°C, respectively. The anhydrous salt can be obtained by carehil removal of water under vacuum, but because of the strong tendency to oxidize and eliminate iodine which occurs on heating the salt ia air, it is often prepared from reactions of lithium metal or lithium hydride with iodine ia organic solvents. The salt is extremely soluble ia water (62.6 wt % at 25°C) (59) and the solutions have extremely low vapor pressures (60). Lithium iodide is used as an electrolyte ia selected lithium battery appHcations, where it is formed in situ from reaction of lithium metal with iodine. It can also be a component of low melting molten salts and as a catalyst ia aldol condensations. 

Lithium Hydroxide. Lithium hydroxide monohydrate [1310-66-3], Li0H-H2 0, is prepared industrially from the reaction of lithium carbonate and calcium hydroxide in aqueous slurries. The calcium carbonate is subsequently separated to yield a lithium hydroxide solution from which lithium hydroxide monohydrate can be crystallized. Lithium hydroxide is the least soluble alkaH hydroxide, and solubiHty varies Htfle with temperature. 

Acetylene is passed for 1 hr through a mixture consisting of 0.5 g (72 mg-atoms) of lithium in 100 ml of ethylene-diamine. A solution prepared from 1 g (3.5 mmoles) of rac-3-methoxy-18-methylestra-l,3,5(10)-trien-I7-one and 30 ml of tetrahydrofuran is then added at room temperature with stirring over a period of 30 min. After an additional 2 hr during which time acetylene is passed through the solution the mixture is neutralized with 5 g of ammonium chloride, diluted with 50 ml water, and extracted with ether. The ether extracts are washed successively with 10% sulfuric acid, saturated sodium hydrogen carbonate and water. The extract is dried over sodium sulfate and concentrated to yield a solid crystalline material, which on recrystallization from methanol affords 0.95 g (87%) of rac-3-methoxy-18-methyl-17a-ethynyl-estra-l,3,5(10)-trien-17jB-ol as colorless needles mp 161°. 

Dimethylphenylsilyl lithium (1 mmol, above THF solution) was added to copper(i) iodide (0.5 mmol) at — 23 °C, and the mixture was stirred at this temperature for 4h. The enone (0.75-0.5mmol) was then added, and stirring was continued at —23 °C for 0.5 h. The mixture was then poured on to ice(25 g)/HCl(5 ml), and extracted with chloroform (3 x 25 ml). The combined extracts were filtered, washed with HCI (25ml, 3m), water (25 ml), saturated sodium hydrogen carbonate solution (25 ml) and water (25 ml), and dried. Concentration and purification by preparative t.l.c. (eluting solvent 3 7 ether petrol) gave the /J-silylketone (40-99%). 

When a solution of lithium enolate 68, prepared by the addition of A(Af-dimethyl-2-trimethylsilylacetamide 67 to a THF solution of LDA, is treated with an equivalent amount of propylene oxide 69, a single product 71 is obtained in 75% yield (equation 25) . This result is rationahzed by assuming an initial addition of 68 at the less substimted side of the epoxide, foUowed by the first observed 1,4-migration of silicon from carbon to oxygen (70 to 71). 

Lithium bromide is prepared by neutralizing lithium hydroxide or hthium carbonate with an aqueous solution of hydrobromic acid, followed by concentration and crystallization ... 

Lithium carbonate is obtained as an intermediate product in recovery of lithium metal from its ore, spodumene (See Lithium). It is prepared by mixing a hot and concentrated solution of sodium carbonate with lithium chloride or sulfate solution. 

Lithium fluoride is prepared by treating an aqueous solution of lithium hydroxide or lithium carbonate with aqueous hydrofluoric acid ... 

Lithium Arsenates.—Lithium Orthoarsenate is obtained as the hemihydrate, 2Li3As04.H30, by the action of lithium carbonate on arsenic acid and allowing the solution to crystallise.4 The anhydrous salt is prepared by recrystallising this hydrate from fused lithium chloride 5 rhombic crystals of density 3-07 at 15° C. are obtained. These are soluble in dilute acetic acid they are extremely stable and may be heated to a white heat without fusion. With excess of arsenic acid the normal salt yields deliquescent rhombic prisms of lithium dihydrogen arsenate, 2LiH2As04.3H20, which with water revert to the normal salt.6... 

Two different eluants were used, lithium carbonate-lithium acetate dihydrate, and copper phthalate. A stock solution of the lithium carbonate-lithium acetate dihydrate eluant was prepared from ACS Certified salts using distilled deionised water with the appropriate dilution to obtain the working eluant. 

Preparation.—Several methods6 have been employed to isolate metallic lithium from its salts. The silicates yield lithium oxide, carbonate, or sulphate by ignition with the corresponding calcium or barium compound.6 The solution obtained by extraction with water is freed from heavy metals by precipitation, and the lithium and other alkali-metal salts present converted into carbonates.7 The methods employed in the separation of the mixed carbonates depend on the comparative insolubility of lithium carbonate in water, and on the... 

Lithium iodide, Lil.—On evaporation of the solution obtained by the interaction of lithium carbonate and hydriodic acid, or barium or calcium iodide, lithium iodide crystallizes in the form of hydrates,7 a trihydrate, dihydrate, and monohydrate having been isolated. Above 300° C. the anhydrous salt is formed, but its action on glass and porcelain at high temperatures has prevented its preparation in the pure state. The boiling-point of the iodide is 1170° C.,8 and the vapour-pressure in atmospheres corresponds with the expression... 

Lithium perchlorate, Li CIO 4.—The perchlorate is prepared by neutralizing perchloric acid with lithium carbonate, evaporating to dryness, extracting with alcohol, and concentrating the alcoholic solution. From aqueous solution the trihydrate, LiC104,3H20, crystallizes. It melts at 95° C., passes into the monohydrate at 98° to 100° C., and into the anhydrous salt at 130° to 150° C. The anhydrous salt melts at 236° C., and is converted with evolution of oxygen into the chlorate and chloride above 380° C.2 Between 4103 C. and 430° C. the decomposition is slow, but it becomes rapid at 450° C.3... 

Lithium sulphite, Li2S03.- Evaporation of the solution obtained by the action of sulphur dioxide on lithium carbonate suspended in water yields the monohydrate, Li2S03,H20 addition of alcohol or ether precipitates the dihydrate, Li2S03,2H20. The sulphite is readily soluble in water, and is susceptible to atmospheric oxidation. Heat expels the water of crystallization, and causes partial decomposition into sulphate and sulphide. Double sulphites of lithium with potassium and sodium have been prepared.1... 

Lithium carbonate, Li2C03.—The carbonate is prepared by boiling a solution of a lithium salt with ammonium, sodium, or potassium carbonate, its slight solubility inducing crystallization and facilitating purification. A process for its manufacture from lepidolite has also been devised.2... 

Lithium Metatungstate cannot be prepared by either of Scheibler s methods, i.e. by neutralising metatungstic acid rvith lithium carbonate, or by adding lithium sulphate to a solution of barium metatungstate. The anhydrous tetratungstate has been prepared (see p. 220). 

The enthalpies of solution of LiOH(cr) and Li2Si0g(cr) in 20 percent HF(aq) at 50 C were measured by Hatton et al. (2). The Li2Si0g sample was prepared from lithium carbonate and silica by fusion under vacuum at 1500 K. Analysis gave 66.74 percent Si02 and 15.12 percent Li. The corresponding calculated values are 66.79 and 15.43. Also present were 0.5 percent K and 0.06 percent Na. Corrections were made for impurities in the enthalpy of formation measurements. The results are given as follows ... 

The fust important test of this methodology came in Hanessian s investigation of the spiroketal portion of avermectin Bu- This highly convergent approach incorporates all the oxidation levels and functionality required for carbons C(15)-C(28), except for the necessity of alkyne to alkene conversion. The lithium alkynide was prepared at -78 C and then mixed with boron trifluoride etherate under the conditions of Yamaguchi (Scheme 19). (Direct condensation of the lithium salt and lactone lead to substantial amounts of a, -unsaturated lactone.) Addition of the lactone in stoichiometric amounts to the solution of the modified alkynide led to the formation of the desired hemiketal in acceptable yield. Further improvements could be obtained by the recycling of starting material. ... 

Amino acids were derlvatlzed with 1-dlmethylamlnonaphthalene-5-sulfonyl chloride (dansyl chloride) according to the procedure of Tapuhl and coworkers (48-50). A 10 M stock solution of twenty common -amlno acids (Sigma Chemical Co., St. Louis, MO) was prepared by dissolving the carefully weighed standards in 0.1 M aqueous hydrochloric acid. Aliquots of this solution were transferred to conical vials, evaporated to dryness, and redlssolved In 500 pL aqueous buffer (0.04 M lithium carbonate, pH 9.5). A 500 jL volume of dansyl chloride solution (5 x 10 3 m in acetonitrile) was added, and the derlvatlzatlon was allowed to proceed In the dark at 35"C for one hour. The reaction was terminated by the addition of 2% methylamlne hydrochloride, and the derlvatlzed sample was analyzed Immediately by mlcrocolumn liquid chromatography with UV-absorbance and LIF detection. 

In the improvement of DNPDOH (2,2-dinitro-1,3-propanediol) [66], used sodium nitrite was reduced from 4 times to the equal amount, the amounts of sodium persulfate and potassium ferricyanide were adjusted, which reduced the impact of carbon emission pollution on the environment, and the cost of synthesis was reduced. The synthesis yield was 68 % after improvement, and lower than the production cost is much lower than that of silver nitration method. Major improvement in electrochemical synthesis of DNPOH is that In the first step, sodium hydroxide solution was added to an aqueous solution of 2-nitropropanol after 45 min of stirring at room temperature, lithium perchlorate solution and sodium nitrite solution were added to prepare the deprotonated 2-nitropropanol solution in the second step, deprotonated 2-nitro-propanol solution is added into the working electrode chamber and the reference electrode chamber of the electrolytic cell, and electrolytic reaction is continued for about 1 h under nitrogen for 20 min. Finally DNPOH will be obtained with a yield of about 40 %. The reaction mechanism is ... 

A 0.25 M solution of lithium carbonate (Li2C03), a drug used to treat manic depression, is prepared. 

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