O. A. Noskova

Evaluation and modification of the initial composition of gabbro-basalt rocks for mineral-fiber fabrication and stone casting

Literature data and calculation results demonstrate that it is appropriate to use the acidity coefficient for the initial evaluation of the properties of gabbro-basalt raw materials for fiber production and stone casting. We examine the capabilities of hydrochloric acid leaching for modifying the composition of raw materials and those of physicochemical calculations for determining the mineralogical compositions of raw materials and modification products.

Effect of iron content on the sintering of ground basalt into ceramics

Ground basalt from the Myandukha occurrence, Arkhangelsk oblast, was divided into magnetically enriched and magnetically deficient components by magnetic separation, and their chemical compositions were determined. We investigated the difference in thermal behavior between the two components using differential scanning calorimetry and thermogravimetry data and the mineralogical composition obtained by thermodynamic modeling of the basalt. The sintering behavior of the magnetic and nonmagnetic components of the ground basalt was examined, and some properties of the resultant ceramic materials were studied.

Effect of the properties of the water sorbent on the heat generation in the Fe-C-NaCl-H2O-O2 system

The water adsorption and retention behaviors of vermiculite, silica gel, activated carbon, and a zeolite are analyzed in relation to their pore structures, and their effects on the dynamics of heat generation in Fe-C-NaCl-H2O-O2-water sorbent systems are investigated.

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.

Phase composition of metamorphosed basalt and its sintering products

The phase composition of metamorphosed basalt from the Myandukha occurrence, Arkhangelsk oblast, has been determined by X-ray diffraction. Using differential scanning calorimetry and thermogravimetry data, we examined the effect of phase composition and particle size on the thermal behavior of ground basalt. The phase composition of the sintering products of the magnetic and nonmagnetic components of the basalt has been investigated.

Criteria for assessing technological properties of gabbro-basalt rocks

Various forms of the acidity coefficients and mineral compositions of gabbro-basalt raw materials from ten Russian deposits are calculated. These data are used to assess the physicochemical and technological properties of the rocks required for mineral fiber production and stone casting. Examples of the regulation of the mineral formation process during the melting and crystallization stages are presented.

Inner-sphere condensation of EtNCO and MeCN through coinsertion into the Re-Cl bond

Reactions of rhenium pentachloride with ethyl isocyanate in dichloroethane and acetonitrile are the first to demonstrate the feasibility of inserting organic isocyanates and nitriles into a rhenium-halogen bond. IR spectroscopy and elemental analysis data show that the addition of one to three ethyl isocyanate molecules in dichloroethane yields ReCl4[N(Et)C(O)n]Cl with n = 1−3, depending on the relationship between the reactants. The reaction in acetonitrile yields a heteromolecular insertion product containing a chain of two isocyanate groups and one nitrile group attached to the same rhenium-chlorine bond: ReCl4[{N(Et)C(O)}2N=C(Me)Cl]. When EtNCS is used instead of EtNCO, the reaction is reversible.

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 (α-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 α-Fe.

Application of magnetic separation for modifying the composition of basalt raw materials

The results of studying the process of modifying the composition of basalt raw materials using the magnetic separation method are reported based on the example of basalt of the Myangdukha deposit (Arkhangelsk oblast). The chemical and phase compositions of magnetically enriched and magnetically depleted fractions have been determined by mass spectrometry and X-ray powder diffraction. The process of sintering these fractions has been studied by the DSC/TG method. The phase composition of sintering products has been studied and some of the physicochemical properties of the obtained samples have been determined.

Use of chemical and metallurgical methods for processing of gabbro-basalt raw material

The recovery of silica and the mixture of iron and aluminum oxides, as well as associated valuable elements, from hydrochloric acid solutions obtained after the desalination of the products of the sintering of wastes of gabbro-basalt raw material with soda by hydrochloric acid has been experimentally studied. A scheme of the integrated utilization of gabbro-basalt raw material involving chemical and metallurgical methods has been suggested.