Lithium chloride electrolysis

Preparation of pure lithium-metal traps and ingots (molten lithium chloride electrolysis). Even if in some older processes the metal was prepared by direct metallothermic reduction of the lithium oxide with magnesium or aluminum, today lithium metal is essentially obtained directly by molten-salt electrolysis of LiCl-KCl according to a process... 

Lithium Chloride. Lithium chloride [7447- 1-8], LiCl, is produced from the reaction of Hthium carbonate or hydroxide with hydrochloric acid. The salt melts at 608°C and bods at 1382°C. The 41-mol % LiCl—59-mol % KCl eutectic (melting point, 352°C) is employed as the electrolyte in the molten salt electrolysis production of Hthium metal. It is also used, often with other alkaH haHdes, in brazing flux eutectics and other molten salt appHcations such as electrolytes for high temperature Hthium batteries. 

Lithium is extracted from the ores lepidolite and spodumene, which contain up to 8% lithium oxide. The ore is converted first to lithium sulfate by acid roasting at 250°C and then to lithium chloride via the carbonate. Electrolysis of the fused... 

The Alcoa (Aluminum Company of America) process involves the electrolysis of aluminum chloride which is carried out in a molten bath of the composition 50% sodium chloride, 45% lithium chloride and 5% aluminum chloride, maintained at 700 °C. The Bayer process, which involves the production of pure alumina by the dissolution of bauxite with caustic soda and which has been described in the chapter on hydrometallurgy, must be taken into account while presenting a complete picture of the aluminum extraction flowsheet. It... 

The electrolyte is made by in situ chlorination of vanadium to vanadium dichloride in a molten salt bath. Higher valent chlorides are difficult to retain in the bath and thus are not preferred. The molten bath, which is formed by sodium chloride or an equimolar mixture of potassium chloride-sodium chloride or of potassium chloride-lithium chloride or of sodium chloride-calcium chloride, is contained in a graphite crucible. The crucible also serves as an anode. Electrolysis is conducted at a temperature about 50 °C above the melting point of the salt bath, using an iron or a molybdenum cathode and a cathode current density of 25 to 75 A dnT2. The overall electrochemical deposition reaction involves the formation and the discharge of the divalent ionic species, V2+ ... 

Benkeser and Tincher 128>, on the other hand, reduced acetylenes preferentially to trans olefins using solvated electrons generated at a platinum cathode by electrolytic reduction of lithium chloride in methylamine [lithium metal is formed from lithium ion at the cathode in this electrolysis its dissolution in methylamine generates the solvated electron and regenerates lithium... 

Lithium is contained in minute amounts in the mineral ores of spodumene, lepidolite, and amblygonite, which are found in the United States and several countries in Europe, Africa, and South America. High temperatures are required to extract lithium from its compounds and by electrolysis of lithium chloride. It is also concentrated by solar evaporation of salt brine in lakes. 

Cyclodehydration of 2-phenylthiocyclohexanone with a variety of reagents yielding 1,2,3,4-tetrahydrodibenzothiophene (64) as an oil has been reported,and represents the simplest way of obtaining this material (88%). Alternatively, reduction of 4-keto-1,2,3,4-tetrahydrodibenzothiophene under Huang-Minlon conditions affords 64 in high yield.Trace amounts of 64 were detected in the reduction of dibenzothiophene with calcium hexamine and during electrolysis in ethylenediamine-lithium chloride solution (Section III, C,4). Peracetic acid oxidizes 64 to its sulfone (65%), which... 

Alkynes can be reduced electrolytically. Internal alkynes gave 65-80% yields of cis alkenes when electrolysed in 10% sulfuric acid in ethanol at spongy nickel cathode [127], or predominantly trans alkenes if the electrolysis was carried out in a methylamine solution of lithium chloride. The yields of the alkenes and the ratios of trans to cis alkenes varied depending on whether the electrolysis was carried out in divided or undivided cells (yields 24-80%, composition of product 89-99% of trans alkene) [379]. 

Lithium chloride is used in the production of lithium metal by electrolysis. It also is used in metallurgy as a eutectic melting composition with potassium chloride (LiCl 41 mol% KCl 59 mol%). Other applications are in low temperature dry-cell batteries as a dehumidifier in air conditioning in welding and soldering flux as a desiccant in fireworks and in mineral waters and soft drinks. 

Lithium cannot be obtained by the electrolysis of aq. soln. of its salts, but L. Kahlenberg obtained it by the electrolysis of soln. of the chloride 14 in pyridine, acetone, or in various alcohols. Silvery white lithium was obtained from a cone, soln. of lithium chloride in pyridine at the room temp, using a graphite plate as anode, and an iron plate as cathode with 0 2 to 0 3 amp. per 100 sq. cm. of cathode surface, and a potential difference of 14 volts. 

W7. Nernst has suggested that the hydrogen in lithium hydride plays the part of a halogen, and likens the reaction LiOH + H2=H20 +LiH with LiOH+HCl =H20+LiCl he shows similarities between lithium hydride and chloride in their crystalline form, at. vol., at. lit., heat of formation, coloration of ultra-violet rays, etc. The electrolysis of molten lithium hydride is also analogous with that of fused lithium chloride. Since lithium hydride is completely hydrolyzed in aq. soln., it is assumed that hydrogen acts as a very weak acid. 

The current primary method for production of lithium is by electrolysis. Spodumene, the most plentiful lithium bearing ore, is beneficiated to 3 to 5% Li20 and heated to 1000°C to convert it from its alpha form to its beta form. The beta form is treated with sulfuric acid to form Li2S04. The Li2S04 is water-soluble and is leached and reacted with sodium carbonate to form lithium carbonate. The lithium carbonate is then reacted with hydrochloric acid to form lithium chloride. Anhydrous lithium chloride is used to produce lithium metal by electrolysis (Austin 1984). 

Electrolytic preparation of sym-triazines has been reported electrolysis at a mercury cathode of N,AT-dimethylcyanamide (45) containing lithium chloride as supporting electrolyte produced... 

The method most generally applied to the isolation of lithium is based on the decomposition of the fused chloride by electrolysis, modifications in practical details having been introduced by various experimenters. Bunsen and Matthiessen1 passed the current from six Bunsen cells through the fused chloride contained in a porcelain crucible, with a carbon rod as anode and an iron wire as cathode. Troost employed a similar method. Guntz2 mixed lithium chloride with potassium chloride, but his product contained 1-3 per cent, of potassium. His current was 10 amperes at 20 volts, with a cathode of iron wire 3-4 mm. in diameter. Borchers3 added chlorides of other alkali-metals and alkaline-earth-metals and a small proportion of ammonium chloride, and employed a current density of 10 amperes per 100 sq. cm. Tucker 4 electrolyzed the chloride without the addition of other material. 

The electrolysis of solutions of lithium chloride in various solvents, such as water, alcohols, glycerol, and phenol, has been investigated by Patten and Mott.9... 

Potassium nitrite, KN02.—The nitrite is made by the reduction of potassium nitrate by heating it alone, or with metals such as lead and iron, or with substances containing sulphur or carbon. It is also formed from potassium nitrate by electrolysis with a silver cathode and a copper anode, the yield being almost quantitative.8 The pure salt can be obtained by precipitating the aqueous solution with methyl alcohol.9 Another method for the production of the nitrite depends on the double decomposition of silver nitrite and lithium chloride.10... 

Jones and Bradshaw [J. Am, Chem, Soc. 54, 138 (1932)] passed a current of approximately 0.025 amp. for 8 hours through a solution of lithium chloride, using a silver anode and a silver chloride cathode 0.73936 g. of silver was deposited in a coulometer. The original electrolyte contained 0.43124 g. of lithium chloride per 100 g. of water, and after electrolysis the anode portion, weighing 128.615 g., contained 0.35941 g. of salt per 100 g. water, while the cathode portion, weighing 123.074 g., contained 0.50797 g. of salt per 100 g. of water. Calculate the transference number of the chloride ion from the separate data for anode and cathode solutions. 

The most commonly used electrlyte in electrolysis mediated by solvated electrons is lithium chloride. The reasons are both its high solubility and the advantage of having in solution lithium ions known to form tight ion pairs. Tetrabuylammonium salts have also been employed successfully, however. 

The proportion of elemental lithium in the total production of lithium and lithium compounds worldwide is ca. 10%. It is exclusively manufactured by melt electrolysis of a mixture of lithium chloride (45 to 55%) and potassium chloride at 400 to 460°C in steel cells with a graphite anode and a steel cathode. The cell voltage is 6.0 to 6.5 V. The metallic lithium formed collects on the surface of the molten salt electrolyte. 

Lithium chloride Lithium chloride is manufactured by the reaction of lithium carbonate with hydrochloric acid. As a result of its high corrosivity special steels and titanium apparatus are used. The main application of lithium chloride is in melt electrolysis in the manufacture of metallic lithium. 

Derivation By electrolysis of a mixture of lithium chloride and potassium chloride, high-temperature extraction from spodumene by sodium carbonate, solar evaporation of lake brines. 

The steps outlined above may also be carried out separately by electrolysis of a hydrochloric acid solution, or hydrogen chloride gas in a fused eutectic of lithium chloride and potassium chloride to obtain hydrogen and chlorine [50]. The chlorine can then be used for chlorination and the hydrogen chloride produced recycled (e.g., Eqs. 8.57-8.59). 

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