Volatile silicic compound oxidation

Boron has a great affinity for oxygen and occurs in nature only in boric acid or borates. Borates are composed from clusters of flat trigonal BO3 and tetrahedral BO4 groups. The structural chemistry of borates is as rich and complicated as those of silicates, borides, or boranes. Boron oxide is an essential part of borosilicate glasses such as Pyrex. Boron halides are volatile molecular compounds. They are Lewis acids and react violently with water. The subhalides consist of boron chains or clusters that have terminally bound halogen atoms. They are substitution derivatives of the lower boranes. 

Organic tellurium compounds and siliceous materials, ie, rock, ore, or concentrates, are fused with mixtures of sodium carbonate and alkaline oxidants, ie, sodium peroxide, potassium nitrate, or potassium persulfate. For volatile compounds, this fusion is performed in a bomb or a closed-system microwave digestion vessel. An oxidising fusion usually converts tellurium into Te(VI) rather than Te(IV). 

The largest differences are for the highly volatile elements that form low-temperature ices and/or exist in gaseous form in the terrestrial atmosphere. The largest depletion is for the noble gases. The depletion sequence for N, C, H reflects the general lack of solid nitrogen compounds in meteorites and the predominance of oxides and silicates. 

The calculations also perhaps explain the difference in composition between the small, Earth-like inner terrestrial planets and the large outer Jovian planets. The terrestrial planets presumably condensed at much higher temperatures and are thus composed of metals, metal oxides, and silicates. The Jovian planets would have formed at far lower temperatures within the primitive solar nebula and consist predominantly of frozen volatile compounds such as methane, water, ammonia, and so on. Finally, a possible case for early layering of the Elarth can be drawn from the calculations within a cooling nebula metallic Fe and Ni would condense first, followed by spinels, pyroxenes and olivines, with a final lower temperature layer of alkali feldspar, metal oxides, hydrated silicates and, of course, water itself at 0°C. 

The type of decomposition of the sample (reactive to use) depends on the nature of the matrix in reactors. Many matrices require HF to break the Si-O bonds of the silicates and HNO3 to oxidize the C. Organic samples (biological, botanical, polymeric pharmaceutical, etc.) and geological samples (soils, sediments, rocks, clays, etc.) are of interest for this type of treatment, since the C and the Si are transformed, by the acids mentioned, to volatile compounds (CO2 and SiF4, respectively) and the... 

A comparatively slow reaction between CsOH vapor and Inconel has been reported by Elrick et al. (1984), with the formation of a cesium silicate or aluminate as a reaction product being assumed. CsOH can also react with various other metals and metal oxides at high temperature, for example with zirconia at 1900 K to form cesium zirconate CS2Z1O3. These reactions indicate that significant retention of cesium can be expected to occur in the primary circuit during a severe reactor accident, since the compounds formed are generally less volatile than CsOH. 

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