Chemical Properties
White powder
Uses
Lithium Metaborate is commonly used as a fused compound or a component for an assay. It has been used for the analysis of wild rice for silicon, calcium, magnesium and potassium. Lithium metaborate was used to fuse with solid samples for decomposition.
Uses
Lithium metaborate is used for flux.
Preparation
Lithium metaborate, LiBO2, may be prepared by fusing together either lithium hydroxide or lithium carbonate and boric acid in the proper stoichiometric ratio. Recrystallization from water at about room temperature yields lithium metaborate- octahydrate, LiBO2·8H2O. The octahydrate may be dried to yield a dihydrate, LiBO2-2H2O, or a half-hydrate, LiBO2·0.5H2O.
General Description
Lithium metaborate (LiBO
2) is the lithium salt of boric acid. It can be synthesized by reacting orthoboric acid with lithium carbonate. Its crystals belong to the monoclinic crystal system having space group
P2
1/
c. Three polymorphic forms have been identified on ambient pressure devitrification of LiBO
2: α-, γ- and β′-LiBO
2.
Flammability and Explosibility
Not classified
Structure and conformation
Lithium metaborate has several crystal forms.
Below 100 °C, LiBO
2·8H
2O is firstly dehydrated to a lower hydrate LiBO
2·2H
2O
[1].
When the temperature is higher than 190°C, the dehydrated amorphous hydrate could crystallize into other poorly crystalline phases designated as LiBO
2·xH
2O (x=0.3/0.5)
[2].
An anhydrous monoclinic α-LiBO
2 could be obtained when the baking temperature reaches 600 °C. The α form consists of infinite chains of trigonal planar metaborate anions [BO2O
-]n.
At 950 °C, by applying 15 kbar of pressure to a LiCl flux containing α-LiBO
2, α-LiBO
2 could be converted to metastable γ-LiBO
2 crystals which were small, but of high quality
[3]. γ-LiBO
2 has tetragonal symmetry with lattice parameter a=4.1961 ?, c=6.5112 ?, space group I-42d and a density of 2.882 g/cm
3.
References
[1] E.I.Kamitsos, A.P.Patsis, M.A.Karakassides, G.D.Chryssikos, Infrared reflectance spectra of lithium borate glasses, Journal of Non-Crystalline Solids, 1990, 126, 52-67.
[2] Li Lei, Duanwei He, Kai He, Jiaqian Qin, Shanmin Wang, Pressure-induced coordination changes in LiBO2, Journal of Solid State Chemistry, 2009, 182, 3041-3048.
[3] Colin D. McMillen, Henry G. Giesber, Joseph W. Kolis, The hydrothermal synthesis, growth, and optical properties of γ-LiBO2, Journal of Crystal Growth, 310, 2008, 299-305.
