Lithium carbonate

Structural formula
General
Surname	Lithium carbonate
Molecular formula	Li 2 CO 3
Brief description	white solid
External identifiers / databases
CAS number 554-13-2 EC number 209-062-5 ECHA InfoCard 100.008.239 PubChem 11125 ChemSpider 10654 Wikidata Q410174
Drug information
ATC code	N05 AN01
properties
Molar mass	73.89 g mol −1
Physical state	firmly
density	2.11 g cm −3
Melting point	720 ° C
boiling point	1310 ° C (decomposition)
solubility	13.3 g l −1 (20 ° C) in water 7.2 g l −1 (100 ° C) in water insoluble in ethanol , acetone
safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed GHS labeling of hazardous substances Caution H and P phrases H: 302-319 P: 305 + 351 + 338
Thermodynamic properties
ΔH f 0	−1215.9 kJ / mol
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Lithium carbonate (technical language) or lithium carbonate (Li ₂ CO ₃ ) is the lithium salt of carbonic acid . Lithium carbonate is the most important lithium compound. As early as 1985, world sales of lithium carbonate were around 28,000 tons / year.

Lithium carbonate occurs very rarely in nature in the form of the mineral zabuyelite .

Extraction and presentation

Lithium carbonate is made from lithium-containing ores ( pegmatites ) and brines . The most important ore is spodumene .

Production of the first technical lithium carbonate began in 1923 in the Hans-Heinrich-Hütte of the metal company in Langelsheim ( Harz ).

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. Further alkalization with sodium carbonate leads to the precipitation of lithium carbonate, which is filtered off or centrifuged off. If the starting material is heavily contaminated, it is dissolved again with sulfuric acid and precipitated with sodium carbonate. Before packaging, the lithium carbonate is dried in a vacuum dryer .

By reacting with carbon dioxide, the water-insoluble lithium carbonate is converted into the metastable lithium hydrogen carbonate (lithium bicarbonate). After the aluminum and iron silicates have precipitated, the lithium hydrogen carbonate is collected and converted back into pure lithium carbonate by heating to 95 ° C.

The processing of brines containing lithium is more economical. They are concentrated before they are precipitated with soda. In the Salar de Atacama extraction area in Chile , this occurs partly through evaporation of the water in solar ponds . The subsequent production process takes place as described above.

properties

Solubility diagram of lithium carbonate in water

Lithium carbonate crystallizes in the monoclinic crystal system in space group C 2 / c (space group no. 15) with the 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 . Phase transitions take place at 350 ° C and 410 ° C. In contrast to the carbonates of the other alkali metals , lithium carbonate is less soluble in water. The solubility decreases with increasing temperature. Therefore, the conversion of aqueous lithium salt solutions with sodium carbonate is a suitable manufacturing method :

${\displaystyle \mathrm {2\ Li^{+}+Na_{2}CO_{3}\longrightarrow Li_{2}CO_{3}+2\ Na^{+}} }$

This solubility behavior is used in the laboratory to purify commercially available lithium carbonate. For this purpose, a cold-saturated solution is prepared, insoluble impurities are filtered off if necessary and then heated to the boil with vigorous stirring. Due to the decreasing solubility of lithium carbonate with increasing temperature, pure lithium carbonate begins to precipitate, which is then filtered off while hot.

Unlike the carbonates of sodium and potassium are dry lithium carbonate when heated carbon dioxide from

${\displaystyle \mathrm {Li_{2}CO_{3}\longrightarrow Li_{2}O+CO_{2}} }$

If lithium carbonate is heated in an electric furnace with an excess of carbon , lithium carbide is formed . Here, too, lithium is more like calcium than the other alkali metals, which are reduced to metal under these circumstances.

${\displaystyle \mathrm {Li_{2}CO_{3}+4\ C\longrightarrow Li_{2}C_{2}+3\ CO} }$

The standard enthalpy of formation of the crystalline lithium carbonate is Δ _f H ⁰ ₂₉₈  = −1215.87 kJ / mol.

use

Half of the sales are required for the production of aluminum ( melt flow electrolysis ). Further areas of application are the glass , ceramic and enamel industries . Lithium carbonate ensures a lower melting temperature - which lowers energy costs - and gives the hot glass mass a lower viscosity (which, for example, facilitates the production of very thin-walled glass).

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 . It is also used to lower the melting point in the electrolytic production of aluminum . Lithium-containing glasses are used to manufacture refractory glasses due to their low expansion coefficient . It is also part of quick-setting cements and screeds and serves the rapid setting of the cement. In molten carbonate fuel cells it is part of the electrolyte . In industry it is also used as a flux for the production of glass, ceramics and enamel.

In lithium therapy , lithium carbonate is used to treat depressive illnesses , manias or bipolar disorders . Trade names are for example in Germany Hypnorex and Quilonum in Austria Neurolepsin and Quilonorm , Switzerland Quilonorm . The dosage must be adjusted carefully, however, as lithium compounds can cause cardiac irritation at higher concentrations or fatal from five grams.

Lithium carbonate

Others

Lithium carbonate is the namesake of the song Lithium by the grunge band Nirvana . The song alludes to the substance's use in treating depressive disorders. The band Evanescence also released a song called Lithium in 2006 , as did the producer Venetian Snares in 2004 with the song Li2CO3 .

literature

• Richard Bauer: Lithium - as it is not in the textbook , Chemistry in Our Time, October 1985, p. 167, VCH Verlagsgesellschaft mbH Weinheim

Individual evidence

1. ↑ ^{a b c d} Entry on lithium carbonate in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
2. ↑ ^{a b} Lithium carbonate data sheet (PDF) from Carl Roth , accessed on December 14, 2010.
3. ^ ^{A b c} E. R. Caley and PJ Elving: Purification of lithium carbonate . In: Harold Simmons Booth (Ed.): Inorganic Syntheses . tape 1 . McGraw-Hill, Inc., 1939, p. 1-2 (English).
4. ↑ Entry on lithium carbonate. In: Römpp Online . Georg Thieme Verlag, accessed on May 30, 2014.
5. ^ ^{A b c} Jean D'Ans, Ellen Lax: Pocket book for chemists and physicists. 3. Elements, inorganic compounds and materials, minerals, Volume 3. 4. Edition, Gabler Wissenschaftsverlage, 1997, ISBN 978-3-540-60035-0 , p. 532 ( limited preview in the Google book search).
6. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-20.
7. ↑ Martin Bertau, Armin Müller, Peter Fröhlich, Michael Katzberg et al .: Industrial Inorganic Chemistry . John Wiley & Sons, 2013, ISBN 978-3-527-64958-7 ( Google Books ).
8. ^ ^{A b c d} A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 1153.
9. ↑ Donald E. Garrett: Handbook of Lithium and Natural Calcium Chloride . Academic Press, 2004, ISBN 978-0-08-047290-4 ( Google Books ).
10. ↑ ^{a b c} R. Abegg, F. Auerbach, I. Koppel: Handbook of inorganic chemistry. Verlag S. Hirzel, 1908, Volume 2, Part 1, pp. 146ff. Full text
11. ↑ Oliver Herzberg: Investigation of organic solid-state reactions using the example of substitution and polycondensation reactions . Hamburg 2000, DNB  960245774 , urn : nbn: de: gbv: 18-2380 (dissertation, University of Hamburg).
12. ↑ ( Page no longer available , search in web archives: Activity report 2005 ) Institute for Wood Technology Dresden
13. ↑ J. Deberitz, G. Boche: Lithium and its compounds - industrial, medical and scientific importance , in: Chemie in our time 2003 , 37 , 258–266, doi: 10.1002 / ciuz.200300264 .