Lithium hydroxide is a white monoclinic fine crystal. It has a spicy taste. Strongly alkaline. It absorbs carbon dioxide and moisture in the air. Soluble in water, slightly soluble in ethanol, insoluble in ether. Corrosive.
Name: Lithium hydroxide
Alias: Lithium hydroxide anhydrous
CAS No: 1310-65-2
EINECS No: 215-183-4
Molecular formula: LiOH
Molecular weight: 23.95
Appearance and traits: white tetragonal crystal
Melting point: 462 ° C
Density: 1.43 g/cm3
Boiling point: 925 ° C
Water solubility: 113 g/L (20 ° C)
pH (1mol/L): 14
Application: For the production of lithium salt and lithium grease, electrolyte for alkaline storage batteries, absorption liquid for lithium bromide refrigerators, etc.
It is easy to absorb carbon dioxide and water in the air, but the absorption capacity is slightly worse than NaOH and KOH. Lithium hydroxide has the property of a base, and the following reaction can occur.
1. Alkaline reaction
The purple litmus test solution can be turned blue, and the colorless phenolphthalein test solution turns red; and the concentrated solution is experimentally verified to denature the phenolphthalein to change the solution from red to colorless (similar to concentrated NaOH).
2. Acid neutralization reaction
3. React with acidic oxides
2LiOH+CO2=Li2CO3+H2O (this reaction is used to absorb carbon dioxide in aerospace)
4. React with metal salt solution
Lithium hydroxide can be used as a developing agent and lubricating oil for spectroscopic analysis. The additive of the alkaline battery electrolyte can increase the electric capacity by 12% to 15% and increase the service life by 2 to 3 times.
It can be used as an absorbent for carbon dioxide to purify the air inside the submarine.
The chemical equation is: 2LiOH(s) + CO2(g) = Li2CO3(s) + H2O(l).
Used for making lithium salt and lithium grease, alkaline battery electrolyte, lithium bromide refrigerator absorption liquid, lithium soap (lithium soap), lithium salt, developer, etc., or as analytical reagents; petroleum, chemical, light industry, Used in nuclear industry, etc.
When used in alkaline storage batteries, the aluminum content is not more than 0.06%, and the lead content is not more than 0.01%. Used as an analytical reagent, photographic developer, also used in the manufacture of lithium; used as a raw material for the preparation of lithium compounds. Can also be used in metallurgy, petroleum, glass, ceramics and other industries.
How to make lithium hydroxide
Lithium hydroxide is usually prepared by slurrying lithium carbonate with lime milk, heating it with water at 100 ° C, and filtering off calcium carbonate. This method is more common.
Metal lithium and water are produced. The raw materials of this method are relatively expensive and relatively rare.
1. The spodumene concentrate (generally containing 6% of lithium oxide), mixed with limestone, sintered at 1150 ~ 1250 ° C to form lithium aluminate and calcium silicate, crushed by wet grinding, leaching lithium hydroxide with washing liquid After sedimentation filtration, the leachate is concentrated by evaporation and crystallized to form a finished lithium hydroxide monohydrate. The chemical equation is:
2. Dissolve industrial lithium hydroxide in cold water under stirring, filter out insoluble matter, and evaporate the filtrate to heat to form crystals. After cooling, the mixture is dried to obtain a lithium hydroxide monohydrate reagent.
3. Using lithium hydroxide monohydrate as a raw material and drying in a desiccator containing phosphorus pentoxide for several days, anhydrous lithium hydroxide can be obtained. It can also be obtained by slowly heating lithium hydroxide monohydrate to dehydration at 140 ° C in a hydrogen stream.
Store in a dry and clean warehouse. Keep away from fire and heat. Protect from direct sunlight. The package is sealed. It should be stored separately from oxidants, acids, carbon dioxide and food chemicals. Avoid mixing. The storage area should be provided with suitable materials to contain spills.