Phase Composition of the Products of Fe Oxidation in Fe + C + NaCl + H2O + O2 Exothermic Mixtures

Using thermodynamic analysis of the Fe–C–NaCl–H₂O–O₂ system and experimental studies (x-ray diffraction and Mössbauer spectroscopy) of exothermic mixtures containing Fe metal, activated carbon, water, and NaCl, we identified the state of Fe and determined the phase composition of the reaction products at different stages of oxidation with atmospheric oxygen. The calculation and experimental results are in reasonable agreement. Under the conditions of restricted access for air, the main oxidation product is magnetite, Fe₃O₄. Free access for air leads to the formation of hydrous ferric oxide, Fe₂O₃ · nH₂O. The most stable phase under the conditions of interest is goethite, Fe₂O₃ · H₂O (-FeOOH). Storage of incompletely oxidized samples away from air for 7–14 days leads to partial reduction of iron(III) oxide phases to Fe₃O₄ and -Fe.     

Methylation as a method for the deep extraction processing of coal

The interaction of brown coal from the Sergeevskoe deposit with methanol under acid catalysis conditions was studied. The role of a catalyst in the processes occurring on methylation was demonstrated. The effect of intermolecular interactions on the solubility of alkylated coal was found. The individual and group compositions of the modified products were examined. It was found that the preliminary alkylating activation of coal facilitated the extraction process and increased the extraction of bitumens, waxes, and tars. Modified coal is a potential source for the production of high-quality crude mineral wax.     

Distribution of 226Ra and 232Th on the radium production waste repository site

Monitoring of the ²³²Th and ²²⁶Ra radionuclides was carried out on the radium production waste repository site. Over the period 1981–2002, the ²³²Th and ²²⁶Ra contents decreased by a factor of 2–2.5. Of much importance in natural deactivation are natural factors that favor normalization of the radiation situation.     

Structure and microhardness of nanocrystalline composite alloys on the basis of Al and Ti

A nanotechnology for production of layered composite nanocrystalline Al-Si, Al(1Hf + 0.2Nb + 0.2Sn, wt %)-Si, Al(0.5Ce + 0.5Re + 0.1Zr, wt %)-Si, and Ti-Si alloys has been suggested. The structure of the nanocrystalline composites obtained has been studied by the methods of optical microscopy and scanning and transmission electron microscopy. Experimental data on the microhardness of layered composite nanocrystalline alloys on the basis of aluminum and titanium are given. The microhardness of the nanocrystalline two-layered Al-Si composite in comparison with submicrocrystalline aluminum increased by a factor of three. In the nanocrystalline two-layered Ti-Si composite (compacted from powders), the microhardness also increased by a factor of almost six in comparison with nanocrystalline titanium. In the nanocrystalline two-layered composite alloys of aluminum, the increase in microhardness in the case of the Al(Hf,Nb,Sn)-Si alloy was up to 45% as compared to the composite on the basis of the metallic foil and by a factor of two as compared to the powder-compact composite; and in the case of the Al(Ce, Re,Zr)-Si alloy, by a factor of 1.6 and 2.7, respectively. An increase in the number of layers in the composites had no significant effect on the level of microhardness.     

Role of Activated Carbon in Chemical Interactions in the Fe–C–NaCl–H2O–O2 Heat-Generating System

Computer simulations of equilibria in the Fe–C–NaCl–H₂O–O₂ system demonstrate that carbon has a significant influence on the composition of iron oxidation products. The effect of activated carbons with different physicochemical properties on the kinetics of heat generation during iron oxidation is studied. The process is shown to depend not only on the specific surface area and porosity of carbon but also on the stability of the complexes formed on the carbon surface via sorption of iron ions.     

Component composition of deresined brown coal wax

The products of the alkaline hydrolysis of wax isolated from brown coal from the Sergeevskoe deposit were studied using chromatography and IR and NMR spectroscopy. It was found that hydrocarbons, alcohols, acids, and a representative fraction of unsaponifiable esters were the constituents of wax. High-molecular-weight fatty alcohols and acids were identified as the constituents of wax with the use of thin-layer chromatography.