Lithium carbonate
N05AN01
White solid
Fixed
2.11 g · cm -3
720 ° C
About 1310 ° C
- Slightly soluble in water: 13 g · l-1 (20 ° C ) in water
- Insoluble in ethanol, acetone
Attention
525 mg • kg -1 ( LD50, rat, oral)
-1215.9 KJ / mol
Template: Infobox chemical / molecular formula search available
Lithium carbonate ( technical terminology ) or lithium carbonate ( Li2CO3 ) is the lithium salt of carbonic acid.
Lithium carbonate is produced from lithium-containing ores and brines.
In 1923 began in the Hans -Heinrich Hut of Metallgesellschaft in Langelsheim ( resin ) the production of the first technical lithium carbonate. Lithium carbonate is the most important lithium compound. Already in 1985, the world sales of lithium carbonate was about 28,000 tons / year.
The lithium-containing ore is crushed, roasted to remove organic impurities and digested with sulfuric acid. By adding sodium carbonate (soda), the impurities are first precipitated and filtered off. Another alkaline with sodium carbonate results in the precipitation of lithium carbonate, is filtered off or centrifuged off. For heavily contaminated starting material is again dissolved with sulfuric acid and precipitated with sodium carbonate. Before packaging the lithium carbonate is dried in a vacuum dryer.
Low-cost is the processing of lithium-containing brines. Before precipitation with soda they are concentrated. In the catchment area Salar de Atacama in Chile, this is partly due to the evaporation of water in solar ponds. The subsequent production route is done as described above.
Properties
Lithium carbonate crystallizes in the monoclinic crystal system, space group C2 / c with lattice parameters a = 835.9 pm, b = 497.67 pm, c = 619.4 pm, and β = 114.72 °. In the unit cell contains four formula units. At 350 ° C and 410 ° C phase transitions take place. In contrast to the carbonates of other alkali metals, lithium carbonate is less soluble in water. With increasing temperature, the solubility decreases. Thus making it the manufacturing method, the reaction of aqueous lithium salt solutions with sodium carbonate to:
Different from the carbonates of sodium and potassium is dry lithium carbonate by heating carbon dioxide from
When heated lithium in an electric furnace with an excess of carbon, the result is lithium carbide. Again, the lithium is more like the calcium as the other alkali metals, which are reduced to the metal under these conditions.
The standard enthalpy of formation of crystalline lithium carbonate is ΔfH0298 = -1215.87 kJ / mol.
Use
The half of the paragraph is required for aluminum production ( fusion electrolysis ). Other areas of application include glass, ceramic, enamel industry. Lithium carbonate provides a lower melting temperature - which reduces energy costs - and gives the hot glass has a lower viscosity ( thereby facilitating the production of very thin-walled glass, for example ).
Lithium carbonate can be used as a starting material for the production of other lithium compounds such as lithium chloride, lithium formate, lithium hydroxide or lithium niobate. Furthermore, it is used for lowering the melting point in the schmelzflusselektrolytischen of aluminum. Lithium -containing glasses are used because of their low coefficient of expansion for the production of refractory glasses. It is also part of quick-setting cements and screeds and is used to rapid setting of the cement. Schmelzcarbonatbrennstoffzellen in it is part of the electrolyte. In the industry it is also used as a flux for the preparation of glass, ceramic and enamel.
In the lithium therapy lithium carbonate is used in the treatment of depressive disorders, mania or bipolar disorders. Trade names are for example in Germany and Hypnorex Quilonum in Austria Neurolepsin and Quilonorm, Switzerland Quilonorm. However, the dosage must be adjusted carefully because lithium compounds can be lethal at higher concentrations to heart or irritation from five grams.
In chemical analysis, the presence of lithium ions in aqueous solution by addition of an alkali metal carbonate, such as sodium or potassium carbonate happen, with poorly water -soluble lithium carbonate precipitates out of solution as a white precipitate.
Others
Lithium carbonate is named after the song lithium the grunge band Nirvana. The song alludes to the use of the substance for the treatment of depressive disorders. The band Evanescence in 2006 published a song called lithium, as well as 2004, the producer Venetian Snares with the song Li2CO3.