N. F. Drobot

Calculation of the mineral composition of basaltic rocks

A technique for the recalculation of data of the chemical analysis of basaltic rocks in terms of mineral composition by the method of physicochemical calculations is proposed. On the basis of data available in the literature on the chemical composition of a series of samples of these rocks, calculations of their mineral composition are carried out. A good correlation of the calculation and experimental data is obtained. The technique proposed can be applied to estimate the mineral composition of raw materials and evaluate the methods of its modification in the technology for obtaining basaltic fibers and stone-cast materials.

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.

Physicochemical simulation of fusion processes of basalt and diabase with Na2CO3 and Na2CO3 + CaO

Fusion processes of basalt and diabase with sodium carbonate and its mixture with calcium oxide are investigated by methods of physicochemical simulation. Equilibrium compositions of the Si-Al-Fe-Ca-Mg-Na system are calculated at various ratios Na2CO3: basalt (diabase) and (Na2CO3 + CaO): basalt (diabase) in the temperature range of 1270–1470 K. It is shown that, on fusion with sodium carbonate, depending on conditions, the main components of fusion products are sodium metasilicate (Na2SiO3) and sodium metaaluminate (NaAlO2), magnesium orthosilicate (CaMgSiO4), sodium ferrite(III) (NaFeO2), iron(III) oxide (Fe2O3), and sodium-aluminum orthosilicate (Na2AlSiO4). On fusion with the mixture of sodium carbonate and calcium oxide, respectively, the products are sodium metaaluminate, calcium pyrosilicate (Ca3Si2O7), calcium-magnesium orthosilicate, and calcium ferrite (CaFe2O4).

Physicochemical modeling of basalt melt generation for petrurgy

Thermodynamic analysis was used to calculate the equilibrium composition of melts of the Si-Al-Ti-Ca-Mg-Fe-K-Na-Ar (O2, H2) systems, which model the generation of various types of basalt melts during heating (within 1573–1773 K) under inert, oxidative, and reductive atmospheres. The results were used to determine the fusion protocol for petrurgical purposes.

Evaluation of the mineralogical composition of gabbro rocks from chemical analysis data

A procedure proposed earlier for calculating the mineralogical composition of basalts from chemical analysis data has been developed further. We have calculated the mineralogical compositions of various gabbro occurrences in Russia. The calculation results correlate well with earlier data on the mineralogical composition of the rocks in these occurrences.

Controlled Oxidation of an Fe + C + NaCl + H2O Mixture: Phase Composition of Reaction Products and Dynamics of Heat Generation

The Fe-containing products of the reaction in an Fe + C + NaCl + H2O mixture were identified by Mössbauer spectroscopy at different stages of oxidation interrupted by storage in an inert atmosphere. The results indicate that the storage of the mixture away from atmospheric oxygen leads to partial reduction of iron oxides. According to thermal analysis data, the energy stored in the heat-generating mixture studied can be used intermittently: heat release rapidly ceases after the mixture is isolated from air and resumes upon further oxidation. The reduction of iron(III) oxides during storage in an inert atmosphere stabilizes the heat-generation parameters at a nearly constant level during multiple oxidation–storage cycles.

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.