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amount of the glass phase is detrimental to the mechanical properties of the mullite that is prepared from kaolinite [ 7 ]. Mechanical activation of the starting materials is a promising method for the precursor's preparation. Particle size

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(e.g., vibratory, oscillating, or planetary milled) [ 12 ]. Mechanical activation, which results in reduced crystalline size and induces residual stress to the particles, is responsible for such a phenomenon. In some cases, chemical reactions may

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-003-0162-5 . 4. Korchagin , MA , Bokhonov , BB 2010 Combustion of mechanically activated 3Ti + 2BN mixtures . Combust Explos Shock Waves 46 2 170 – 177 10.1007/s10573-010-0026-4 . 5

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Abstract  

The electrogenerative-leaching of galena activated mechanically in planetary centrifugal mill were studied. A dual cell system was introduced to investigate the leaching process. The experimental results indicated that the mechanical activation improved the galena’s lattice constant, the lattice distortion and the degree of crystal defect, which resulted a decreasing of initial potential of galena electrode and an increasing of output voltage of the leaching cell.

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The physical mixtures of hydroxocarbonates of Cu and Ni with aluminium were activated using a laboratory planetary mill. The chemical reactions and alloy formations as the effects of grinding were followed by the phase analysis of solid products based on the thermogravimetry and X-ray diffractometry. Experimental evidence indicates that the nature of reactions and products of mechanical activation was dependent on the amount of aluminium and time of grinding.

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The changes in specific surface area and structure disorder of mechanically activated arsenopyrite were investigated. The rate of nonoxidative decomposition of mechanically activated arsenopyrite was increased almost 10-times when compared with nonoxidative decomposition of a non-activated sample. An empirical linear relationship was found (r=0.996) between the rate constant of decomposition and the ratio of specific surface to transmission of the absorption band of arsenopyrite at
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\bar \nu = 370 cm^{ - 1}$$ \end{document}
. This relationship enables us to arrange the reaction 4FeAsS→4FeS+As4 among structure-sensitive reactions.
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use of mechano-chemistry for production of glass, glass–ceramics, and other glass-derived materials. The polymeric structure of glasses allows one to expect that mechanical activation will have an effect on the thermal transformations of glasses

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Abstract  

A catalytic action of the mechanochemical products of copper hydroxocarbonate with calcium carbonate was investigated in n-butyl alcohol oxidation tests. The solid products of high-energy milling were identified using thermogravimetry supplemented by X-ray diffraction method. It was shown that the mechanical activation induces more effective tested catalyst because it promotes the alcohol conversion at lower temperatures than that unmilled one.

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In this paper the reduction of lead and zinc sulphide by hydrogen is described. It has been found that the rate of formation of elemental lead or zinc is favourably affected by mechanical activation of PbS and ZnS produced by intensive grinding. This effect was observed in the region 678–1048 K for galena and in the region 851–1023 K for sphalerite. It has appeared that disordering in the structure of both minerals results in the decrease in experimental activation energy.

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Abstract  

The reduction of cinnabar (HgS) and stibnite (Sb2S3) by hydrogen was investigated. These investigations were performed in the temperature region 636–765 K for cinnabar and in the region 825–954 K for stibnite. It has appeared that the mechanical activation positively affects the thermal reduction of the sulphides. The thermal decomposition of HgS is accompanied by a change in mechanism taking place at 744 K. As to Sb2S3, the change in mechanism inthe investigated temperature region was not observed.

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