Lithium tetraborate

Lithium tetraborate [1303-94-2], is used as a flux in ceramics and in x-ray fluorescence spectroscopy. The salt has also been proposed for... 

The commercial ores, beryl and bertrandite, are usually decomposed by fusion using sodium carbonate. The melt is dissolved in a mixture of sulfuric and hydrofluoric acids and the solution is evaporated to strong fumes to drive off siUcon tetrafluoride, diluted, then analy2ed by atomic absorption or plasma emission spectrometry. If sodium or siUcon are also to be determined, the ore may be fused with a mixture of lithium metaborate and lithium tetraborate, and the melt dissolved in nitric and hydrofluoric acids (17). 

MzBA Na B Oj Lithium tetraborate Sodium tetraborate c CaCNj... 

Figure 4. FTIR. spectra a) crystalline, anhydrous lithium tetraborate b) hydrated, crystalline lithium tetraborate c) difference spectrum (55 hour spectrum - 27 hour spectrum) during polymerization in methoxyethanol d) difference spectrum (48 hour spectrum - 24 hour spectrum) during polymerization in THF.

Lithium sulfuryl chloride batteries, 23 654 Lithium SVO cells, speciality for military and medical use, 3 430t Lithium t-butoxide, 15 148 Lithium tetraborate, 15 137 Lithium tetrafluoroborate, in lithium cells, 3 459... 

Probably the most common fluxes are sodium carbonate (Na2C03), lithium tetraborate (Li2B407), and lithium metaborate (LiB02). Fluxes maybe used by themselves or in combination with other compounds, such as oxidizing agents (nitrates, chlorates, and peroxides). Applications include silicates and silica-based samples and metal oxides. 

Sahoo SK, Masuda A (1995) Simultaneous measurement of lithium and boron isotopes as lithium tetraborate ion by thermal ionization mass-spedrometry. Analyst 120 335-339... 

The presence and concentration of various metallic elements in petroleum coke are major factors in the suitability of the coke for various uses. In the test method (ASTM D5056), a sample of petroleum coke is ashed (thermally decomposed to leave only the ash of the inorganic constituents) at 525°C (977°F). The ash is fused with lithium tetraborate or lithium metaborate. The melt is then dissolved in dilute hydrochloric acid and the resulting solution is analyzed by atomic absorption spectroscopy to determine the metals in the sample. However, spectral interferences may occur when using wavelengths other than those recommended for analysis or when using multielement hollow cathode lamps. 

Melting of samples is necessary for performing the analysis of ceramics and glass materials by means of x-ray fluorescence (XRF). Lithium tetraborate is added as flux for lowering the melting temperature. The homogeneous disks that form can be considered a solid solution of the sample compounds in the binder. 

Most fusions use lithium tetraborate (Li2B407, m.p. 930°C), lithium metaborate (LiB02, m.p. 845°C), or a mixture of the two. A nonwetting agent such as KT can be added to prevent the flux from sticking to the crucible. For example, 0.2 g of cement might be fused with 2 g of Li2B407 and 30 mg of KI. 

Siliceous materials—Si, Al, Fe, Ti, Ca, Mg, Na, K, Mn, Ni, Ba, Ag, Au, Ca, Cr, Cu, Ga, In, Mo, Sb and Zn—may be analyzed by a lithium tetraborate fusionr-acid dissolution technique using atomic absorption spectroscopy. Mercury, tin, and lead volatilize by this technique, and gold and silver in concentrations above 0.5 wt% cannot be held in solution. Coal ash is preconcentrated prior to analysis, and there is possible silica interference. Analytical results, where possible, are compared statistically with other reported values. 

The introduction of atomic absorption spectroscopy has resulted in major advances in the rapid analysis of many elements. Initially, atomic absorption was applied only to aqueous systems or to materials that could be readily solubilized. There are methods to analyze major elements in such complex materials as silicates and vitreous siliceous coal ashes (1-5). More recently, lithium metaborate has been reported to be a good fluxing agent (6) and has also been used in conjunction with atomic absorption analysis in silicate analysis (7). This paper describes a lithium tetraborate-atomic absorption analytical technique which is being used to analyze coal ash. 

Preparation of Standards. Standards for ash analysis were prepared from commercially available pure salts in aqueous solution with appropriate acids addition where necessary to match acid concentrations in the samples as well as to hold materials in solution. Master standard solutions were prepared so that serial dilutions for the construction of working curves were possible. A constant amount of silicon and aluminum (equivalent to 20% Si-5% Al) interference solution was added to each set of standards along with lithium tetraborate to carefully match... 

Although detectable concentrations for several elements could be found after fusion, it is felt that the volatility of mercury and possibly lead and tin would make their determination by lithium tetraborate fusion questionable. Table I shows the elements selected for analysis and the accuracy and precision data for the standards used to check the fusion method. Each standard in Table I was of known composition and siliceous in nature. The standards were separately prepared 10 times so that a statistical evaluation of the results could be made. The standards used were USGS Standards G-2, W-l, BCR-1, commercially prepared silica-alumina based standards, and unfused synthetic standards prepared by the Coal Research Bureau (9, 10, 11, 12). The synthetic standards were used because no commercially prepared standard having... 

The application of the lithium tetraborate fusion technique to the analysis of siliceous ashes has resulted in over 10,000 elemental determinations. While detectable gold and silver concentrations have been found, the results are near the detection limits for those two elements. 

Lithium tetraborate has been found to be an excellent fusion agent enabling complete dissolution of silicate materials in acid for the analysis of major and minor constituents in coal. Carefully prepared standards matching the approximate concentrations of both the silica and alumina present in unknown samples permit determinations to be made with precision and accuracy. This method is currently being used to analyze coal ash and related materials. 

In ferrous metallurgy background correction is mainly used after fusion, when light absorption occurs on salt particles because of high total salt concentrations. By dissolving the fusion substance in inorganic acids, such as HC1, alkali halides develop in high concentration (NaCl, KC1 with soda-potassium fusions LiCl with lithium tetraborate fusions etc). These result in the molecular absorption already described. 

In the form of a solid solution (or pearls) by dilution in a flux powder based on a mixture of lithium metaborate and lithium tetraborate (analysis of major elements)... 

A blank solution is made by first fusing 175 mg of lithium tetraborate in a rhodium-platinum crucible further treatment is the same as that described for the samples. 

Claisse Fluxer Analysis - Lithium tetraborate or metaborate fusion for the dissolution of rocks has been in use for many years. The Claisse Fluxer fusion device simply makes this fusion automated. We have used the method in the past for the fusion of coal and fly ashes (10,13). Oil shales can be dissolved by this method without pre-ashing. Once the solution is prepared, it may be analyzed for the most part by ICPES or by AAS. Analysis of U.S.G.S. Devonian Ohio shale SDO-1 by fusion followed by AAS or ICPES measurements is illustrated in Table III. 

Element wt % Lithium Tetraborate Fusion Parr Acid No Ashing Digestion Bomb Preashing... 

Lithium metaborate, LiBOi, by itself or mixed with lithium tetraborate, finds considerable use in attacking refractory silicate and alumina minerals, particularly for... 

The most popular and elegant specimen preparation technique introduced by Claisse 17] is based on fusion of solid specimens with lithium tetraborate. The method was used with great success in our laboratory for the rapid quantitative X-ray fluorescence analysis of silicates, bricks, refractories, limes, iron, and manganese ores. The use of lithium tetraborate and lithium fluoride flux systems was therefore examined first. 

A small amount, 2.5 to 3.0 g of representative gypsum specimen, was calcined for 1 h at 1000°C in a platinum crucible, and the loss on ignition was recorded. A portion of 1.0000 g of the calcined specimen was mixed with 6.000 g of dense lithium tetraborate (Spectroflux 100 , Johnson and Matthey Co.) and 0.3000 g of lithium fluoride. Approximately 3 mg of lithium bromide was added to the mixture as a release (nonsticking) agent. Fusions were carried out on a propane flame, using a Claisse fluxer (2] equipped with crucibles and molds made from 95% platinum-5% gold alloy. The volume of molten flux was adequate to fill the 32-mm diameter mold to a sufficient height and produce a disk approximately 4 mm thick. 

When lithium tetraborate and lithium fluoride are used as a flux, or when... 

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