52 research outputs found
Role of acid-base interactions in synthesis of cordierite from talc and sillimanite group minerals
It has been found that the mechanical activation of mixtures of sillimanite
group minerals with talc and silica additives in grinding-activating devices
with periodic and flow action provides significant acceleration of their
interaction with formation of cordierite at the subsequent high-temperature
treatment. It is shown that the output of cordierite depends on nature of
mineral: in mixture with a sillimanite it is considerably higher, than with
an andalusite and kyanite, while the rate of mullitization of these minerals
has opposite character. It means that the formation of mullite during heat
treatment is not a limiting step in synthesis of cordierite. It is shown that
the rate of reaction is determined by the difference in the acid-base
properties of these minerals, which depend on the coordination of aluminum
cations by oxygen ions, different for each of the modifications
Sillimanite group minerals: a new promising raw material for the Russian aluminum industry
Chemistry for Sustainable Development 20 (2012) 297301 Effect of Mechanical Activation on the Kinetics of Kyanite Mullitization
Abstract The kinetics of mullitization of kyanite samples, both initial and mechanically activated in high-energy grinding devices within temperature range 12731573 K was investigated. It was shown that the kinetics of kyanite mullitization formally corresponds to the equation of monomolecular decomposition. The activation energy of this transformation is (630±10) kJ/mol. It was established that mechanical activation of kyanite accelerates mullitization processes during subsequent thermal treatment. The yield of mullite per unit surface area is almost two times higher for mechanically activated sample than for non-activated one. Possible mechanism of mullitization process and technological aspects of the implementation of this process in industry are discussed
Analysis of experimental data on the diffusion coefficients of Fe, Mn, Mg, and Ca in garnets
Mass transfer at the contact of high-Al metapelites and metabasites: An example of the high-temperature Sharyzhalgai Complex, Eastern Sayan
Dependence of the water content in channels of the cordierite structure on the composition of its Fe-Mg solid solutions
Geochemical specifics and 40Ar/39Ar age of the basaltoid magmatism of the Alexander Land, Northbrook, Hooker, and Hayes islands (Franz Josef Land Archipelago)
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