The surface properties and the density of melting products significantly influence the separation of metallic and slag phases in a metallothermic process and correspondently influence the formation of a final alloy as an ingot. There are poor data in the literature on surface and interfacial properties of aluminum–titanium alloys containing rare refractory metals. The aim of this work is to study the surface and volumetric properties of contacting phases using experimental and computational methods and to analyze the revealed dependences. The interaction of a base Al–Ti alloy containing tantalum, niobium, and vanadium up to 4 at

The density and surface tension of homogeneous molten slags from the joint smelting of nickel saprolite and copper pyrite ores have been experimentally assessed (maximum bubble pressure method) using model samples of iron-containing slage (8.9 wt.

Выполнена экспериментальная (метод максимального давления в газовом пузыре) оценка плотности и поверхностного натяжения гомогенных расплавленных шлаков совместной плавки силикатной никелевой и медной колчеданной руд. Измерения проведены на модельных образцах: железистого, масс. % (8,9 CaO; 11,8 MgO; 12,5 Al2O3; 47,4 SiO2; 13,3 FeO и 5,0 Fe2O3) и образованного при удалении из него оксидов железа безжелезистого, масс. % (12,5 CaO; 16,0 MgO; 9,4 Al2O3 и 58,3 SiO2) шлаков, отражающих состав и структуру реальных прототипов, в интервалах температур 1550–1300 °C и 1550–1400 °C соответственно. Снижение температуры ведет к повышению плотности и поверхностного натяжения указанных шлаков в диапазонах 1,85–2,21 и 2,23–2,29 г·см–3 и 144–250 и 340–345 мН·м–1 соответственно. Структурные изменения при переходе от первого состава ко второму вызваны сокращением основности с 0,7 до 0,6 и заменой Fe2+ на Ca2+ и Mg2+. Второй фактор вносит основной вклад в рост как самих характеристик, так и их температурных коэффициентов (от –0,0015 до –0,0004 г·см–3·°C–1 и от –0,4 до –0,1 мН·м–1·°C–1 соответственно). Методом регрессионного анализа экспериментальных данных получены эмпирические модели, позволяющие достоверно прогнозировать величину плотности и поверхностного натяжения реальных шлаков рудной плавки медного и никелевого сырья в рассмотренном диапазоне температур. Результаты работы могут быть использованы при разработке и совершенствовании металлургических технологий, а также процессов стекольной и керамической промышленности. An experimental (method of maximum pressure in a gas bubble) assessment of the density and surface tension of homogeneous molten slags from the joint smelting of nickeliferous saprolitic and copper pyrite ores has been carried out. The measurements were made on model samples of iron-containing (8.9 wt. % CaO; 11.8 wt. % MgO; 12.5 wt. % Al2O3; 47.4 wt. % SiO2; 13.3 wt. % FeO and 5.0 wt. % Fe2O3) and formed upon removal of iron oxides from it iron-free (12.5 wt. % CaO; 16.0 wt. % MgO; 9.4 wt. % Al2O3 and 58.3 wt. % SiO2) slag, reflecting the composition and structure of real prototypes, in the temperature ranges of 1550–1300 °C and 1550–1400 °C, respectively. A decrease in temperature leads to an increase in the density and surface tension of these slags in the ranges of 1.85–2.21 and 2.23–2.29 g·cm–3 and 144–250 and 340–345 mN·m–1, respectively. Structural changes during the transition from the first composition to the second are caused by a reduction in basicity from 0.7 to 0.6 and the replacement of Fe2+ by Ca2+ and Mg2+. The second factor makes the main contribution to the growth of both the characteristics themselves and their temperature coefficients (from –0.0015 to –0.0004 g·cm–3·°C–1 and from –0.4 to –0.1 mN·m–1·°C–1, respectively). Using the method of regression analysis of experimental data, empirical models have been obtained that make it possible to accurately predict the density and surface tension of real slags from the smelting of copper and nickel raw materials in the considered temperature range. The results of the work can be used in the development and improvement of metallurgical technologies, as well as in the glass and ceramic industries.

— Cooling of a melt with the composition Bi 2 O 3 ·SiO 2 and the metastable phase Bi 2 SiO 5 under various conditions has been studied by computer simulation with ProCAST software. Using previously reported thermophysical characteristics (thermal conductivity, heat capacity, and density) of the melt and metastable phase and the experimentally determined thermal diffusivity of the metastable Bi 2 SiO 5 compound in the range 299–700°C, we have evaluated the cooling rate, which has been shown to agree well with the experimentally determined one, confirming that the assumptions made in our simulations are quite adequate.

The devitrification, “cold” crystallization, and glass transition temperatures and melting point of samples in the B2O3–CaO–Al2O3–PbO system have been determined by differential thermal analysis. The viscosity of aluminum calcium borate melts containing up to 6.9% PbO has been measured in the temperature range 1153–1573 K. The results demonstrate that lead oxide additions reduce melt viscosity and that the density and surface tension of the melts increase with increasing lead oxide content and decrease with increasing temperature. High- and low-temperature regions have been identified where the melts have properties of Newtonian fluids. Cooling leads to polymerization and vitrification of the melts.

The possibility of modeling the cooling processes of the Bi2GeO5 metastable compound using the ProCAST software package is shown. Despite a number of assumptions used in the simulation, the calculation results showed good convergence with the real cooling rates of the melts and can be useful for the development of modeling in the Bi2O3 – GeO2 system in order to obtain metastable materials with a given set of properties and the character of the microstructure.

Boron oxide-based systems are used for refining metals in pyrometallurgical units and for simulating various metallurgical processes. The aim of this work is to determine the viscosity and electrical conductivity of B 2 O 3 –CaO–FeO melts as functions of the composition and temperature. The work presents the results of measuring the viscosity and the electrical conductivity of the B 2 O 3 –CaO systems at B 2 O 3 /CaO of 3.0, 1.86, and 1.22, respectively, with FeO additives up to 20%. The measurements are carried out in a wide glass-formation temperature range. The viscosity is measured by oscillatory viscometry. The electrical conductivity is measured by a contact method using an ac bridge. The temperature dependences of the viscosity and the electrical conductivity are measured in the temperature range 1100–1750 K. An increase in the melt temperature is shown to lead to a decrease in the viscosity (η) and to an increase in the electrical conductivity (æ) of the melts. In the temperature ranges ( T max – T 1 ) and ( T 1 – T 2 ) corresponding to the high and low temperatures zones of the homogeneous melts, the viscosity and the electrical conductivity exhibit linear dependences in the ln(η)–1/ T and ln(æ)–1/ T coordinates. The activation energies of the viscous flow ( E η ) and the electrical conductivity ( E ϰ ) are determined. At high temperatures, the activation energy of the viscous flow of the melts changes from 13 to 103 kJ/mol and changes from 59.7 to 185 kJ/mol as temperature decreases. A comparison of E η and E ϰ shows that their ratio is not a constant value. This fact indicates that groups responsible for the viscous flow and the electrical conductivity are different. In the temperature range T 2 – T min , there is a segment with a nonlinear dependence, where glass transition occurs over the entire range of changes (B 2 O 3 /CaO is 3.0). The glass transition takes place up to temperatures of 1150 K (B 2 O 3 /CaO is 1.86) with subsequent formation of crystallites and with partial solidification of the melt in the measurement temperature range (B 2 O 3 /Ca is 1.22). The results are used to describe the structures of the borate melts. In addition, the information obtained is useful for recommending the melt compositions used for refining metals in pyrometallurgical units.

The possibility of modeling the processes of cooling of the metastable Bi2GeO5 compound in the ProCAST software package is demonstrated. Despite a number of assumptions that are made in the modeling, the calculated data are shown to be in good agreement with the real melt cooling rates and can be used in the development of modeling in the Bi2O3–GeO2 system to obtain metastable materials with a desired set of properties and a microstructure.

Physical and chemical properties of Ti-Al-(Nb, Ta, V) alloys obtained by joint aluminothermic reduction of metals from the oxides were studied. It was found that an increase in temperature from 1500 to 1625 degrees C contributed to a linear decrease in the density and surface tension of the alloys. Increasing concentration of Nb, Ta and V to 3.5 mol. % affected the increase in the values of these properties.

During the melting processes in steel-melting aggregates, lining destruction takes place due to the Magnesium oxide of lining dissolution in slag. In this study, different materials containing Magnesium oxide have been introduced into slag to increase lining stability. Efficiency estimation of raw siderite (10-0 mm class) using for this aim is considered in the present work. Initial slag (basic capacity СаО/SiO2=2,1) of industrial ASM (Arc Steel Melting) was corrected by high magnesia introduction additives (siderite). Slag has been loaded into a magnesia crucible, heated up to 1700∘C, aged during 1 hour and cooled with the furnace. The final slag phase composition analysis detected considerable changes in it: increase of MeO-phase refractory with MgO prevalence (melting temperature 2800 ∘С) and replacement of monocellitic silicate component (CaO⋅MgO⋅SiO2, melting temperature 1498 ∘С) by larnite (β-2CaO ⋅SiO2 melting temperature 2130 ∘С). Crucible slag resistance was estimated by thinning of it walls. Experiment results confirmed affect of MgO content in slag to linings solubility in it. It was determined that siderite additives increase MeO-phase (melting temperature more than 2000 ∘С) content in slag approximately by 30 % that is rather essential for lining service period increasing. It is confirmed that siderite additives prolongate magnesia lining stability of steel-making aggregates. Keywords: Bacal siderite, refractory lining, steel-making aggregates, crucible, monocellit, magnesia

To estimate the size of the drops formed on individual bubbles of the reducing gas during the oxide melt barbotage, a metal phase formation model was used. This model includes the following stages: formation of bubbles upon injection of gas into the melt; metal recovery on the bubbles surface and its concentration in the form of drops in stern. Equations are presented that make it possible to estimate the limiting sizes of a gas bubble (Rкрп) and drops (rкрк) moving in oxide melt without crushing. Using the densities (p, kg/m3) and surface tension (σ, mJ/m2) of B2O3 - CaO (1) and B2O3 - CaO - CuO (2) melts in the temperature range of 1373 - 1673 K, described by the equations σ1= 87,0 + 0,242T, p1 = 3,2610-3 - 0,91T, σ2= 10,8 + 0,178T, p2 = 3,1910-3 - 0, 70T, respectively , the critical dimensions of a gas bubble (Rкрп)moving in an oxide melt without crushing were calculated. In B2O3 - CaO - CuO melt, critical radius of the bubble varies from 0.047 to 0.053 m depending on temperature, and for the B2O3 - CaO system these values are 0.06 - 0.081 m. Using a technique with thermodynamic equilibrium calculations that allows to describe the features of oxide melt barbotage by various reducing gases, we determined the change of the copper oxides content in B2O3 - CaO - CuO melt depending on the amount of CO introduced at different temperatures. Based on the obtained data, the amount of copper formed during the interaction of Cu2O in the melt with a single CO bubble wascalculated depending on the content of copper oxide and the amount of CO in the bubble. The correlation dependences of the drop size on the content of Cu2O in the melt (CCu O, %), temperature (T, K) and the amount of CO in the bubble (nCO , mol) were obtained by statistical data processing methods.

At present, during solving theoretical and applied problems of metallurgical technologies improving, thermodynamic modeling (TDM) methods are widely used to calculate multicomponent and multiphase systems. However, existing methodology TДM are intended for the balance analysis in the ”closed” systems. The authors of [9] proposed a technique that allows, using TDMs, to describe metal reduction processes during gas bubbling of multicomponent oxide melts in approximation to “open” real systems. The applicability of the methods is estimated using the example of joint Nickel and Iron reduction modeling in the B2O3-CaO-FeO-NiO system by Carbon monoxide for ”open” and ”closed” systems. The data obtained comparison for ”open” and ”closed” systems show that the consecutive output of products (gas and metal) from working medium promotes achievement of the best parameters for Nickel extraction to alloy and to its residual content in oxide melt. Using this technique, the TДM process of joint reduction of Nickel and Iron in system B2O3-CaO-FeO-NiO by Carbon monoxide in ”open” system was undertaken at various temperatures in the 1273-1773K interval. Keywords: thermodynamic modeling, ”closed” system, ”open” system, joint reduction, Carbon monoxide, oxide melt, gas bubbling

Boron oxide-based systems on structure and properties are similar to silicate systems, but they are more fusible and so are widely used in modelling various metallurgical processes. This paper presents the results of viscosity, electrical conductivity, surface tension and density measurements of the B2O3–CaO system with a content of 25–45% CaO in the temperature range above the liquidus temperature. To measure viscosity, vibration viscometry was used. Electrical conductivity was measured via the contact method using an alternating current bridge. Surface tension and density were measured using the lying drop method. The obtained results were used to describe the structure of borate melts.

Cu–W composite alloys are obtained using the liquid-phase impregnation method of noncompacted W powders and sintered porous W and W + Cu specimens. The structure of the alloys and its influence of pre-crystallization processing by low-frequency oscillation (LFO) on the “Cu melt–W powder” compositions are investigated. The technological parameters of obtaining low-porosity (1–2%) alloys are defined. It is proved that varying the thermo-time LFO exposure makes it possible to modify the W concentration in the matrix, creating the composite layers with high tungsten content (80–90%). The LFO treatment of the “copper melt + noncompacted W powders” compositions has a number of advantages compared to the routine (liquid-phase impregnation of compacted tungsten powder) industrial technology of production of Cu–W alloys. There are significant reduction of stages (up to 1–2), the possibility of replacement of working atmospheres (hydrogen, vacuum) by cheaper “Ar + CO,” and the dispersion of W phase.

Density and surface tension of ferronickel and oxidized Nickel ore melts are measured. Interfacial tension at this phases border at the 0 – 100 mas. % of nickel content in the metal phase and temperature range 1550 – 1750 °С is measured as well. Experimental results are generalized in the form of functional dependencies relating density, surface and interfacial tension with temperature and composition. The obtained data may be used for metallic phase formation processes analysis at the barbotage treatment of oxidized Nickel ore by carbon monoxide. Density and surface tension of the molten ferronickel (0 – 100 % Ni), and oxidized nickel ore melts (mas. %: 14.8 Fetotal , 7.1 FeO, 13.2 Fe2 O3 , 1.4 CaO, 16.2 MgO, 54.5 SiO2 , 4.8 Al2 O3 , 1.5 NiO, 1.2 Cr2 O3 ) are measured by the of sessile drop method as well as the interfacial tension at the interface boundary in the 1550 – 1750 °C temperature interval. This alloys density varies from 7700 to 6900 kg/m3 , oxide melt density – from 2250 to 1750 kg/m2 , surface tension – from 310 to 290 mJ/m2 . Obtained results agree well with the literature data. Functional temperature and concentration dependencies of density, surface and interfacial tension of the melts are presented. Temperature and concentration dependencies of the alloys meet fi rst order equations. Similar form has temperature dependence of surface and interfacial tension, while concentration dependence on nickel corresponds to the second order equation. The density and surface tension of the oxide melt meet linearly temperature dependence. The obtained results are supposed to use for description of metal phase formation in barbotage process of oxide melt by carbon monoxide.

The density and surface tension of melts of ferronickel (0–100% Ni) and oxidized nickel ore are measured by the sessile-drop method, as well as the interface tension at their boundary in the temperature range 1550–1750°C. The composition of the nickel ore is as follows: 14.8 wt % Fetot, 7.1 wt % FeO, 13.2 wt % Fe 2 O 3 , 1.4 wt % CaO, 16.2 wt % MgO, 54.5 wt % SiO 2 , 4.8 wt % Al 2 O 3 , 1.5 wt % NiO, and 1.2 wt % Cr 2 O 3 . In the given temperature range, the density of the alloys varies from 7700 to 6900 kg/m 3 ; the surface tension from 1770 to 1570 mJ/m 2 ; the interface tension from 1650 to 1450 mJ/m 2 , the density of the oxide melt from 2250 to 1750 kg/m 3 ; and its surface tension from 310 to 290 mJ/m 2 . The results are in good agreement with literature data. Functional relationships of the density, surface tension, and interphase tension with the melt temperature and composition are derived. The dependence of the alloy density on the temperature and nickel content corresponds to a first-order equation. The temperature dependence of the surface tension and interphase tension is similar, whereas the dependence on the nickel content corresponds to a second-order equation. The density and surface tension of the oxide melt depend linearly on the temperature. The results may be used to describe the formation of metallic phase when carbon monoxide is bubbled into oxide melt.