The Reduction of Boron By Silicothermal Method

Thermodynamic modeling (TM) of the boron reduction process from the CaO–SiO2– MgO–B2O3 oxide system by silicon of ferrosilicon of FeSi65 and FeSi75 grades has been carried out. TM is made using the HSC 6.12 Chemistry software package developed by Outokumpu Research Oy (Finland). The equilibrium composition of oxide CaO-SiO2-MgO-B2O3 and metallic Si-Al-Fe systems was determined using the Equilibrium Compositions module in a given temperature range of 1400–1700∘C and a gas phase pressure of 1 atm. The effect of silicon of ferrosilicon grades (FeSi65 and FeSi75) on the degree of boron reduction (

Obtaining of niobium-containing ferroalloys from the Russian ore raw materials

The possibility of processing niobium-containing pyrochlore-apatite concentrates obtained from ores of Beloziminskoye deposit has been studied. A two-stage scheme for selective reduction of phosphorus into a metal phase to obtain low-phosphorus niobium-containing slag was suggested. The reduction of phosphorus and iron was carried out by a carbothermic method using coke and pig iron carbon as the reducing agent. Pig iron chip and magnetite product (80 % Fe2O3) were used as the precipitating agent. In laboratory and semi-industrial conditions the basic possibility of selective separation and sedimentation of phosphorus (to 91 %) and iron from a niobic concentrate without considerable reduction of niobium (up to 1-2 %), according to the two-stage scheme with minimum possible temperature of process during the first period (∼ 1260 C) and hot soak at the increased temperature (∼ 1450 C) during the second period were shown. Obtained low-phosphorus niobium-containing slag after crushing can be used for ferroniobium production according to existing technological schemes. © Published under licence by IOP Publishing Ltd

A Jupiter-mass planet around the K0 giant HD 208897

For over 10 years, we have carried out a precise radial velocity (RV) survey to find substellar companions around evolved G,K-type stars to extend our knowledge of planet formation and evolution. We performed high precision RV measurements for the giant star HD 208897 using an iodine (I2) absorption cell. The measurements were made at T\"UB\.ITAK National Observatory (TUG, RTT150) and Okayama Astrophysical Observatory (OAO). For the origin of the periodic variation seen in the RV data of the star, we adopted a Keplerian motion caused by an unseen companion. We found that the star hosts a planet with a minimum mass of m2sini=1.40MJ, which is relatively low compared to those of known planets orbiting evolved intermediate-mass stars. The planet is in a nearly circular orbit with a period of P=353 days at about 1 AU distance from the host star. The star is metal rich and located at the early phase of ascent along the red giant branch. The photometric observations of the star at Ankara University Kreiken Observatory (AUKR) and the HIPPARCOS photometry show no sign of variation with periods associated with the RV variation. Neither bisector velocity analysis nor analysis of the Ca II and Halpha lines shows any correlation with the RV measurements

Steel Micro-alloying with Boron: A Perspective Direction to Reduce the Consumption of Manganese Ferroalloys

Manganese ferroalloys occupy a strategically important place in the total production of ferroalloys, since no steel grade can be made without the manganese addition. Today, the metallurgical complex of Russia is fully dependent on imports of manganese products (raw ore and ferroalloys), so special attention should be paid to the issues of more rational use of manganese. In particular, one should more widely use the methods of direct micro-alloying of steel with manganese in steel-smelting units and ladle-furnaces unit (LFU) and expand the range of high-strength steel with reduced manganese content, micro-alloyed with high-performance elements. Among the micro-alloying elements, a special place is occupied by boron. Its introduction into the metal in the amount of 0.001–0.005% makes it possible to save expensive and scarce alloying elements, in particular manganese, and to provide an increase in the strength of steel without reducing ductility. The results of the studies of the physicochemical properties of slags of the system CaO–SiO2–B2O3–Al2O3–MgO had formed the basis for the technology development for the formation of basic boron-containing slags, that implementation at the LFU in the converter shop of JSC “ArcelorMittal Temirtau” provided the smelting of boron-containing steel economically doped with manganese with low-content of sulfur and high strength and plastic properties. The developed technology provided, depending on the steel grade, a boron content of 0.001–0.008% by weight, low concentration of sulfur in the metal, not more than 0.004–0.014% by weight, and reducing the manganese ferroalloys consumption from 0.5 to 1.4 kg/ton of steel. Keywords: pipe steel, manganese, sulfur, boron, mechanical properties, structur

Additional spectroscopic redshift measurements for galaxy clusters from the First Planck Catalogue

We present the results of spectroscopic redshift measurements for the galaxy clusters from the first all-sky Planck catalogue of the Sunyaev-Zeldovich sources, that have been mostly identified by means of the optical observations performed previously by our team (Planck Collaboration, 2015a). The data on 13 galaxy clusters at redshifts from z=~0.2 to z=~0.8, including the improved identification and redshift measurement for the cluster PSZ1 G141.73+14.22 at z=0.828, are provided. The measurements were done using the data from Russian-Turkish 1.5-m telescope (RTT-150), 2.2-m Calar Alto Observatory telescope, and 6-m SAO RAS telescope (Bolshoy Teleskop Azimutalnyi, BTA).Comment: published in Astronomy Letter

Mathematical modelling of the process of melting alloys of the Si-Cr-Ni-Fe system in the iron-carbon melt

The process of melting of the Si-Cr-Ni-Fe ferroalloys in the iron-carbon melt under static conditions was studied using the method of mathematical modelling. It was found that the melting process takes place in three stages. The effect of silicon concentration and the initial size of a piece of alloy on the duration of each stage of alloy melting is revealed. It was shown that an increase in the silicon content from 6 to 40 % in the complex ferroalloy of the 50 mm fraction containing ∼ 27 % Cr and ∼ 12 % Ni leads to a decrease in the total melting time of the alloys from 67 to 30 seconds at the iron-carbon melt temperature of 1600 °C. © Published under licence by IOP Publishing Ltd

Особенности ректификационного разделения многокомпонентных смесей

Objectives. To improve the process of developing energy-efficient flowsheets for the distillation separation of multicomponent aqueous and organic mixtures based on a comprehensive study of the phase diagram structures, including those in the presence of additional selective substances.Methods. Thermodynamic-topological analysis of phase diagrams; modeling of phase equilibria in the AspenTech software package using the equations of local compositions: Non-Random Two Liquid and Wilson; computational experiment to determine the column parameters for separation flowsheets of model and real mixtures of various nature.Results. The fractionation conditions of the origin multicomponent mixture due to the use of sharp distillation, pre-splitting process, extractive distillation with individual and binary separating agents were revealed. The columns operation parameters and the energy consumption of the separation flowsheets ensuring the achievement of the required product quality with minimal energy consumption were determined.Conclusions. Using the original methods developed by the authors earlier and based on the generalization of the results obtained, new approaches to the synthesis of energy-efficient multicomponent mixtures separation flowsheets were proposed. The provisions that form the methodological basis for the development of flowsheets for the separation of multicomponent mixtures and supplement the standard flowsheet synthesis plan with new procedures were formulated.Цели. Совершенствование процесса разработки энергоэффективных схем ректификационного разделения многокомпонентных водных и органических смесей на основе комплексного исследования структуры фазовой диаграммы, в том числе в присутствии селективных дополнительных веществ.Методы. Термодинамико-топологический анализ фазовых диаграмм; моделирование фазовых равновесий в программном комплексе AspenTech с использованием уравнений локальных составов Non-Random Two Liquid, Вильсона; вычислительный эксперимент по определению параметров работы колонн схем разделения модельных и реальных смесей разной природы.Результаты. Выявлены условия фракционирования исходной многокомпонентной смеси за счет использования промежуточного заданного разделения, предварительного расслаивания, экстрактивной ректификации с индивидуальными и бинарными разделяющими агентами. Определены параметры работы колонн и энергозатраты схем разделения, обеспечивающие достижение требуемого качества продуктов при минимальных энергозатратах.Выводы. С использованием разработанных ранее авторами оригинальных методик и на основе обобщения полученных результатов предложены новые подходы к синтезу энергоэффективных схем разделения многокомпонентных смесей. Сформулированы положения, которые составляют методологическую основу разработки принципиальных схем разделения многокомпонентных смесей и дополняют типовой план синтеза схем новыми процедурами

Physical and dynamical parameters of the multiple system HD 222326

We present the results of our study of the physical and dynamical parameters of the multiple system HD 222326. A new method for determining the individual radial velocities of components in wide binary and multiple systems in the case of small radial-velocity differences (δV r the FWHMfor the line profiles) is suggested and tested for both model systems and the binary HD 10009. This testing yielded the component radial velocities V r 1,2 for HD 10009, enabling us to derive the center-of mass velocity, V γ, for the first time. We determined the radial velocities of the components of HD 222326 from high-resolution spectra, and refined the orbital parameters of the subsystems using speckle-interferometric observations. A combined spectroscopic and speckle interferometric analysis enabled us to find the positions of the components in the spectral type-luminosity diagram and to estimate their masses. It is likely that the components are all in various evolutionary stages after leaving the main sequence. We analyzed the dynamical evolution of the system using numerical modeling in the gravitational three-body problem and the known stability criteria for triple systems. The system is probably stable on time scales of at least 106 years. The presence of a fourth component in the system is also suggested. © 2008 Pleiades Publishing, Ltd

V1327 aquilae: A new RR lyrae variable with an extremely high radial velocity

We have carried out photometry and spectroscopy of the star V1327 Aql (R = 16 m ) as part of our program of observations of poorly studied cataclysmic variables using the 1.5-m optical Russian-Turkish telescope (RTT-150, Turkey) and the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. After analyzing our photometry, we have re-classified the variable as an RR Lyrae star. Our BV R photometry during 10 nights reveals brightness variations with the period 12 h49 m, with the B, V, and R amplitudes being 1.36 m , 1.13 m , and 1.11 m , respectively. We derived the first estimates of the star's atmospheric parameters from our moderate-resolution spectra: T eff = 6280 K, log g = 3.3, [M/H] = -1.05. The extremely high radial velocity of the star's motion (V R = -470 km/s) and the star's large distances to the Galactic center (13.1 kpc) and disk (4.2 kpc) testify to a probable extragalactic origin of this object. © 2008 Pleiades Publishing, Ltd