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Data on the volumes of imported and exported materials of the metallurgical industry in Russia are presented. The domestic industry, despite the rich mineral resource base, depends on imported supplies for a whole list of ore concentrates, oxides and other compounds, metals, and ferroalloys, as well as for certain grades of steel and metal products, which leads to high risks in the field of the country's security and sustainable development. The authors analyze the situation associated with the dependence on supplies of ore materials, metals, and alloys from abroad and give examples of promising technological options for the development of domestic production using Russia's own mineral resource base. [ABSTRACT FROM AUTHOR]

Samples of titanium-containing slag of AO EVRAZ NTMK from blast furnace processing of Ural titanomagnetite ore concentrate of the Kachkanar deposit were investigated to study the possibility of titanium extraction. The initial samples differed in the crystallization method. One sample was obtained by layer-by-layer pouring of slag into the trench and cooling it with water (hereinafter referred to as fast crystallization slags). The other sample was made of slag crusts that remained in a slab after draining its liquid part (hereinafter referred to as slow crystallization slags). The chemical and phase compositions of all studied samples were similar; the content of TiO2 was about 10.5%. The main phase (matrix) was akermanite-gehlenite, which was approximately 65%. The titanium-containing phase was perovskite of about 26%. The fast crystallization slags were characterized by a fine structure of the titanium-containing phase with an average particle size of about 13 μm. The titanium-containing phase consisted of 88% of particles with an area of more than 100 μm2 with an average particle size of 17 μm. The slow crystallization slags were characterized by a larger structure of the titanium-containing phase, the size of such particles was ~30 μm. The titanium-containing phase consisted of 92% of large particles with an area of more than 500 μm2 with an average particle size of about 40 μm. For mechanical enrichment, it is preferable to use slags with slow crystallization characterized by large inclusions of the titanium-containing phase — perovskite. The size of the titanium-containing phase and the density ratio of perovskite and akermanite-gehlenite (matrix) at the level of 1.35 make it possible to investigate the mechanical separation possibility of titanium-containing concentrate by density on a concentration table. [ABSTRACT FROM AUTHOR]

Results are provided for experimental-industrial tests of high-carbon ferrochrome smelting with partial replacement of the basic chromium ore with chromium ore briquettes produced by OJSC Donskoi Ore Mining and Processing Plant in an amount of 20–40% of the chromium ore raw material supplied to TNC Kazchrome JSC Aksu Ferroalloys Plant (Kazakhstan). These tests show that use of chromium ore briquettes has a number of technological advantages. When using briquettes instead of ore, there is a reduction in electricity consumption from 7201 to 6184 kWh/ton, and chromium extraction increases from 80.3 to 85.3%. Use of briquettes solves the problem of involving substandard chromium ore raw materials in production and improving technical and economic performance of the furnace. [ABSTRACT FROM AUTHOR]

Abstract—The physicochemical and service properties of new complex Nb–Si–Al–Fe–Ti alloys containing (wt %) 0–25 Si, 20–23 Nb, 5–6 Al, and 3–4 Ti are studied and compared with the well-known two-component Fe–60% Nb alloy. The two-component Fe–Nb alloy belongs to the group of super-refractory ferroalloys with a solidification temperature of 1720°C. A decrease in the niobium concentration and an increase in the content of Si, Al, and Ti make it possible to transfer the alloys to the group of refractory ferroalloys with a melting temperature of 1550–1584°C. The lowest solidification temperature (1550°C) is characteristic of an alloy containing the maximum silicon content (25 wt %) and the minimum niobium content (20 wt %). A pycnometric study of the densities of the complex ferroalloys shows that an increase in the silicon concentration to 21–25 wt % leads to a decrease in the alloy density to optimum values (5000–7000 kg/m3). The melting of the complex niobium alloys with a lump diameter of 2–100 mm in an iron–carbon melt under static conditions has been studied by mathematical modeling. The melting of all complex alloys is found to proceed in three stages. Due to high melting temperatures, super-refractory ferroalloys, which include the two-component alloy with 60 wt % Nb, dissolve at the temperature of liquid steel; therefore, their assimilation mechanism proceeds in two stages. The alloy containing 25 wt % Si and 20 wt % Nb has the shortest melting time at all lump sizes. The ferroalloy lump size is shown to affect the melting/dissolution time most strongly. This is explained by the fact that the alloy mass increases with the lump size, which brings about an increase in the heat content and the frozen steel skin thickness. The complex alloys are shown to have the most favorable densities and solidification temperatures as compared to standard ferroniobium. The alloy containing (wt %) 25 Si, 20 Nb, 5 Al, and 3 Ti has the best complex of physicochemical and service properties. [ABSTRACT FROM AUTHOR]

The paper provides brief information about the state of production and use of niobium in steelmaking and about niobium deposits in Russia. Pyrochlore-apatite ores contain a significant amount of phosphorus; therefore, the schemes of their enrichment include a dephosphorization stage, which reduces the niobium extraction into the product, increasing its cost. The possibility of improving the through production scheme, including the enrichment of ores and the smelting of niobium ferroalloy, is shown. The smelting process and the physicochemical characteristics of the used concentrates of the CaO– SiO2–MgO–Al2O3–TiO2–Nb2O5–Fe2O3–P2O5 system have not been sufficiently studied; therefore, thermodynamic simulation of carbothermal and metal-thermal processes of reducing the oxide system components was performed in order to determine the influence of chemical composition of the system, the amount of reducing agent and temperature on the reduction degree of elements, the composition of the metal and oxide phases, and the metal dephosphorization. Thermodynamic simulation was carried out for temperatures of 1400–1700 °C at a reducing agent consumption of 80, 100 and 120% of the stoichiometrically required amount for the reduction of the system leading elements. With the carbothermal method, the phosphorus reduction occurs quite completely at more than 100% of carbon of the stoichiometrically required amount already at 1100°C and above. With the silicothermal method, the influence of temperature and silicon amount on the reduction degree of Nb, P, Ti and the chemical and phase compositions of the alloy is shown. [ABSTRACT FROM AUTHOR]

Abstract—Comprehensive information is provided on the physicochemical processes and technology for producing high-silicon alloys and their production waste. Data on the chemical and phase compositions of the resulting slags and dust are presented. The methods of using ferrosilicon fines formed during its crushing, namely, suspension casting with feeding of fines to a conveyor casting machine and briquetting, are described. The methods of using gas-cleaning dust for the production of silicon ferroalloys consisting of microsilica and carbon are overviewed. [ABSTRACT FROM AUTHOR]

Under contemporary conditions of social development, it is necessary to rethink the role of waste produced due to economic activity and, in particular, industrial formations of the ferroalloy industry. In order to evaluate the expediency of involving industrial formations in the production process and substantiate the efficiency of design solutions in the field, a functional approach was proposed and its algorithm created in the Tekhnogen-Invest software. This article continues a study aimed at assessing the efficiency of processing industrial formations of the ferroalloy industry. In this part, the developed software was tested using data from the production of high-carbon ferrochrome. The relevance of the applied methodology for assessing the ecological and economic efficiency associated with processing industrial formations of ferroalloy production is confirmed, taking into account the strategic flexibility of projects. The conducted testing the developed Tekhnogen-Invest software produced positive results. The algorithm used in the software allows the cost of implementing an investment project for processing industrial formations of high-carbon ferrochrome production under current conditions of the Urals to be evaluated and the feasibility of its implementation under changing market conditions to be substantiated. The obtained results demonstrate a high potential for producing marketable products from ferroalloy industry waste, confirming the economic efficiency and feasibility of processing industrial formations. [ABSTRACT FROM AUTHOR]

The contemporary problem of recycling technogenic mineral formations (TMFs) of ferroalloy production under the conditions of increasingly stringent social and ecological constraints is analyzed. During the first decades of the 21st century, management outcome requirements in the metallurgical industry have been significantly toughened. In accordance with international practice, financial and economic indicators connected with maintaining the competitiveness of the industry are typically provided by metallurgical companies. However, in order for the metallurgical industry to remain competitive under these new conditions, it must ensure not only sectoral, but also national-economic effectiveness connected, first of all, in terms of achieving social and ecological goals. In the field of ferroalloy production, the already stressed ecological situation is significantly complicated by the need to apply low-quality (i.e., having an increased content of harmful impurities) mineral raw materials, resulting in a reduction of the technical and economic indices of ferroalloy production. The low utilization degree of valuable alloy components is connected with losses during mining and ore concentration processes, as well as at the stages of ferroalloy production and steel smelting. As a consequence, the total recovery proportion of manganese and chromium into finished products does not exceed 30–40% of that obtained in mining. In order to evaluate the expediency of involving technogenic formations in production process and substantiate the effectiveness of design solutions in this field, the authors propose an interdisciplinary functional approach, an algorithm for which was constructed using the Tekhnogen-Invest software program. [ABSTRACT FROM AUTHOR]

To develop new ferroalloys of a rational composition, data on their physical and chemical characteristics are needed. One of the main characteristics of the alloy, on which the assimilation and distribution of the main elements of ferroalloys in the iron-carbon melt depends, is the duration of its melting. The melting time of complex nickel-containing ferroalloys in liquid steel has been studied using a mathematical model for calculating the melting time developed by researchers from Ural Federal University and Institute of Metallurgy of the Ural branch of the Russian Academy of Sciences. The program allows one to calculate the temperature of a piece of ferroalloy, the thickness of the steel crust being frozen, the size of the piece of alloy and the duration of melting periods depending on the physicochemical and thermalphysic characteristics of ferroalloys. The melting mechanism of ferroalloys determines the time of their melting in liquid steel. Mathematical modeling of the melting of complex nickel ferroalloys containing 10% Ni; 0.5–55.0% Cr; 0.2% C; and 0.2% Si in an iron-carbon melt is performed. It has been established that all the alloys under consideration belong to the group of low-melting ferroalloys and the process of their melting proceeds in three periods. With an increase in the initial size of a piece of ferroalloy from 3 to 100 mm, the melting time increases by a factor of 250–300. It is shown that an increase in the chromium content in the composition of the complex alloy to 37% leads to a decrease in the melting time, and with its further increase to 55%, an increase in the melting time occurs. A decrease in the temperature of the liquid steel bath from 1700 to 1520°C is accompanied by an increase in the duration of melting of complex ferroalloys by 7–8 times. In general, the considered complex nickel ferroalloys are characterized by a much faster melting process in liquid steel compared to standard ferrochromium and ferronickel. [ABSTRACT FROM AUTHOR]

The second part of the article presents perspective directions of using boron and its compounds in the preparation processes, metallurgical processing of ore materials and steel smelting in order to improve the quality of the final product. An efficient technology of silicothermal production of ferrosilicoboron containing 0.6–2.0% B and 60–80% Si has been developed. The advantage of this scheme is the possibility of obtaining a boron-containing alloy during ferrosilicon smelting. It has been experimentally shown that ferrosilicoboron has higher performance characteristics than ferroboron both in production and when used for steel processing. The industrial test results of the technology for microalloying pipe grades of steel with a new ferroalloy with boron confirmed a high degree of boron assimilation—up to 96%. The possibility of widespread use of boron for steel microalloying is due to its cheapness, availability and environmental friendliness. According to the calculations, boron from complex ferrosilicoboron is the cheapest trace element used to increase the strength characteristics of steel. Additives of B2O3 can be successfully used to form high-magnesium liquid steel-making slags. It is shown that 0.37–0.55% B2O3 effectively stabilizes the highly basic slags of the steel and ferroalloy industries. This operation allows obtaining a marketable lump material. The above review as well as the results of the laboratory and industrial studies have shown the effectiveness of boron usage at different stages of metallurgical production. An increase in technical and economic indicators of production and quality of steel and ferroalloys, as well as effective disposal of waste slags, is shown. The technical solutions advanced and tested at metallurgical enterprises do not require capital expenditures. They are implemented by adding microdosing of boron and its compounds to metallurgical production facilities. [ABSTRACT FROM AUTHOR]

Based on literature and our own data, the effect of boron on the characteristics of all stages of metallurgical processes (from sintering, smelting of cast iron and ferroalloys, to steel production) and on the properties of the resulting slag and metal was studied. To intensify hardening of the pellets at the stage of liquid-phase sintering and to improve their metallurgical properties, it is sufficient to have 0.20–0.35% of boron oxide in them. According to laboratory studies, the presence of boron oxide in pellets increases their compressive strength by 1.5–1.7 times and hot strength by 3–4 times. While studying the mechanism and kinetics of sulfur removal, it was shown that the presence of boric anhydride significantly intensifies processes of ±pellets desulfurization. Their intensive progress goes to the zones of lower temperatures of 1050–1100°C. To increase the sinter strength characteristics, it is possible to add B2O3 to the charge. The introduction of 0.44% of B2O3 does not affect the sinter abrasion. The content of fines (0–5 mm) in comparison with the base sample is reduced by 1.5 times. The use of boron pellets in blast-furnace smelting makes it possible to increase the basicity of the final slag from 1.10 to 1.16. In this regard, the sulfur distribution coefficient increases from 48 to 74. The sulfur content in cast iron decreases by 0.005%. The possibility of using boron and its compounds to improve the technical and economic indicators of production and pellet quality, sinter and cast iron is shown on the base of the presented theoretical, laboratory-experimental and industrial data. [ABSTRACT FROM AUTHOR]

Information about the wastes of chromium ferroalloy production in the Russian Federation, their characteristics, and composition is given. The fractional compositions of powdered slags and dust are studied. The true densities of self-disintegrating slags and dust are determined by the picnometric method. New data on the viscosity and solidification temperature of the slag and dust melts of ferrochrome production are obtained, and their phase composition is studied. [ABSTRACT FROM AUTHOR]

The possibility of preparing complex vanadium-containing ferroalloys directly from vanadium slag and their application in steelmaking are considered in a review. Complex alloys make it possible to expand the ore base for ferroalloy production since it may involve poorer and more complex charge materials. Due to this it is possible to regulate parameters of the production process of their preparation more flexibly. Dependences of the physicochemical and thermophysical properties of complex ferroalloys (melting temperature, density, heat capacity, thermal conductivity, melting time in liquid steel, changes in steel temperature during ferroalloy introduction) on the concentration of vanadium, silicon, titanium and manganese in the ferroalloy are studied. The most favorable effect on properties of the ferroalloys studied appears to be an increase in silicon concentration, in view of which with complex vanadium ferroalloy it is useful to include an element such as silicon, and the vanadium-containing oxide component of the charge may be leaner with respect to the basic element content than commercial vanadium pentoxide. Use of vanadium converter slag makes it possible to exclude the vanadium pentoxide preparation stage from the production chain for processing vanadium. It is beneficial for production because vanadium pentoxide processing is characterized by a high level of environmental pollution and loss of vanadium (about 25%). Use of complex vanadium ferroalloys during steel treatment demonstrates the expediency of their use. Combined introduction of vanadium with silicon, calcium, and manganese into a steel melt makes it possible to create a favorable composition and shape for non-metallic inclusions. The main advantages of preparing and using complex vanadium ferroalloys are demonstrated. [ABSTRACT FROM AUTHOR]

Information on the wastes of ferroalloy production in the Russian Federation, their quantity, and composition is provided. For the melting volume of all types of ferroalloys of about 1.7 mlt t, ~1.1 mln t slag and ~125.5 ths t dust and slime are shown to form at Russian plants. 44% of manganese, 30% of chromium and 18% of silicon alloys of their total amount are produced in the world, and 25, 23 and 44%, respectively, are produced in the Russian Federation. The chemical compositions of the main groups of ferroalloys are given. The sectors of the national economy in which the slags and dusts of ferroalloy production can be used are indicated. The main directions of work needed to decrease the amount of wastes and to use them more efficiently are determined. [ABSTRACT FROM AUTHOR]

The key problem of ferroalloy production in Russia is the availability of crude ore. Only few types of alloys are produced at domestic plants from domestically-produced raw materials (ferrosilicon, vanadium alloys). The bulk of ferroalloys is either imported from abroad or smelted from imported raw materials. The development of ferroalloy production is a challenging situation for Russia: raw material import addiction in the presence of large domestic mineral and raw material base, but substandard in terms of world standards quality. One of the main reasons for this situation (in addition to organizational and financial ones) is a well-established conservative approach to the ferroalloy smelting technology using the same type of crude ore and obtaining products as per GOST Standard. Domestic ferroalloy raw materials, as a rule, are of low quality. They have a low content of main elements (manganese, chromium ores), a high content of phosphorus (manganese, niobium ores), and sulfur (manganese ores). This requires physical and chemical studies and the development of new alternative technologies. It is possible to create new technology processes and different ferroalloy combinations that are not inferior in terms of their technical and economic indicators to products obtained from imported non-traditional domestic ore crude, based on deep physical, chemical and technological studies. For solving the domestic crude ore problem found in the ferroalloy industry, it is necessary for scientists, geologists, processing experts and metal-makers to work together. [ABSTRACT FROM AUTHOR]

Thermodynamic simulation of chromium reduction from the oxide system of the composition (wt %) was conducted as follows: 25.0–37.5 CaO, 25.0–12.5 SiO2, 25.0 Cr2O3, 5.0 FeO, 14.0 MgO, 3.0 MnO, and 3.0 Al2O3. Silicon of FeSi20, FeSi45, and FeSi65 ferrosilicon grades was used as a reducing agent in an amount of 110% for the quantity stoichiometrically required for the reduction of iron, manganese, and chromium. The simulation was performed using the HSC Chemistry 6.12 software package developed from Outokumpu, Finland. Calculations were performed using the "Equilibrium Compositions" module in the initial nitrogen atmosphere at a total pressure of 0.1 MPa within the temperature range 1500–1700°C at a temperature increment of 50°C. The thermodynamic characteristics of the CrO(II) compound were entered into the software package's database. The thermodynamic constants of CaCr2O4 available in the database were adjusted. The calculated results are represented in the graphic dependence form of changes in the reduction degree of chromium ηCr on the temperature T, the slag basicity (CaO)/(SiO2), and the silicon concentration in ferrosilicon [Si]FeSi. It is shown that the increase in the process temperature from 1500 to 1700°C at (CaO)/(SiO2) = 2 decreases ηCr by 1.87, 6.04, and 7.38% when FeSi20, FeSi45, and FeSi65, respectively, are used as reducing agents. It has been found that the increase in (CaO)/(SiO2) from 1 to 3 at a temperature of 1600°C results in an increase in ηCr by 17.3, 14.2, and 12.5% when FeSi20, FeSi45, and FeSi65, respectively, are used as reducing agents. The increase in the silicon concentration in ferrosilicon from 20 to 65% [Si]FeSi increases ηCr by 9.5, 5.9, and 4.2% at a slag basicity of 1, 2, and 3, respectively, at a temperature of 1600°C. The metal's chemical composition has been determined. The thermodynamic simulation results can be used to calculate the reduction degree of chromium from the reduction period slags of the argon–oxygen refining during stainless steel production. [ABSTRACT FROM AUTHOR]

The structure and the physicochemical properties of nitrided chromium- and manganese-based ferroalloys have been studied experimentally. Nitrogen in the alloys is shown to be mainly in the form of nitrides Mn2N, CrN, and Cr2N, the fractions of which are dependent on the nitrogen content and the methods of alloy manufacture. The liquidus temperature of the nitrided chromium-bearing ferroalloys is lower than that of analogous nitrogen-free ferroalloys, which positively influences the rate and degree of assimilation of elements by steel. The introduction of 8–16% nitrogen in the ferroalloy compositions decreases their real densities, which enables one to produce alloys with the optimal density. The apparent densities of the nitrided chromium and manganese ferroalloys are very low (3000–4200 kg/m3) due to their high porosity; as a result, they will be melted at the steel melt surface and will have a low degree of nitrogen assimilation. Higher degrees of nitrogen assimilation can be achieved as powdered alloys are injected in a gaseous nitrogen jet. The degree of transition of nitrogen to steel from the ferroalloys is 47–84%; it is mainly dependent on the holding time of a nitrided steel in liquid state, the physicochemical characteristics of nitrided ferroalloys, the composition of an alloyed metal, and the types and content of nitride-forming elements (Cr, Mn, Ti, etc.) in it. The highest degree of transition of nitrogen to steel (84%) was reached using an as-cast nitrided chromium sample with 8% N in the first minute of holding. Further holding up to 30 min of the liquid sample at 1500°C leads to a decrease in the degree of nitrogen assimilation to 52%. [ABSTRACT FROM AUTHOR]

The results of a thermodynamic simulation of the reduction of the elements of the oxide system corresponding to the chromium ore composition (%) 40 Cr2O3, 21 FeO, 15 Al2O3, 6 SiO2, 16 MgO, 2 CaO, and 0.006 P2O5 by the silicon of ferrosiliconickel (28 Fe, 65 Si, 7 Ni) are presented. The HSC Chemistry 6.12 software (Outokumpu Research Oy, Finland) is used for the simulation. The thermodynamic simulation is performed for seven compositions of an ore–lime mixture differed in the CaO content (17–55%). The calculations are performed using the Equilibrium Compositions module at 1700°C, the reducer consumption 1.05mred (mred is the reducer weight stoichiometrically necessary for the reduction of chrome and iron), and the gas phase pressure 0.1 MPa (1 atm). The main results of the calculations performed are given in graphical dependences of the change in the degree of reduction of chromium (ηCr), the amount of silicon used in reduction (φSi), and the chemical compositions of the metal and slag on the slag basicity (CaO)/(SiO2) and the reducer consumption. The degree of reduction of chromium increases by 32.7% (from 64 to 95.1%) in the range of an increase in the slag basicity from 0.07 to 1.86 at φSi = 94.5%. The rational basicity of slag is shown to be 1.86–1.9. The metal of the following chemical composition is formed: 50.4 Cr, 1.97 Si, 3.3 Ni, 0.21 Al, 0.0050 P, and Fe for balance. The influence of the amount of reducer on the degree of reduction of chromium and the chemical compositions of the metal and slag at 1700°C and a slag basicity of 1.86 is studied. An increase in the reducer consumption from 0.5mred to 1.05mred makes it possible to increase the reduction of chromium by 52.4% and to reach ηCr = 95.1%, which is close to the industrial parameters of low-carbon ferrochrome manufacturing. 100% degree of reduction of chromium is achieved at the reducer consumption 2.5mred. The results of the thermodynamic simulation can be used for technological calculations of the reduction of chromium ore elements by ferrosiliconickel. [ABSTRACT FROM AUTHOR]

The melting of nitrided Cr–N–Fe–Si–Al ferroalloys in an iron–carbon melt under static conditions is studied by mathematical simulation. The influence of the initial ferroalloy lump sizes, the chromium content in ferroalloy, and the iron–carbon melt temperature on the alloy melting time is determined. The introduction of 12% chromium into the composition of a low-carbon FKh010 ferrochrome is shown to decrease the temperature of the end of solidification of the ferroalloy, and it passes from the group of high-melting to the group of low-melting alloys. As a result, the mechanism of melting the ferroalloy in an iron–carbon melt changes, and the time of its melting in steel decreases, especially at low temperatures (1540–1560°C). An increase in the chromium content from 61 to 74% at 12–16% N in the alloys under study transfer them from low-melting to high-melting ones, which is accompanied by a sharp increase in the time of melting the ferroalloys in an iron–carbon melt. The temperature of the steel to be processed significantly affects the ferroalloy melting time. The sharp decrease in the total melting time of FKhN20 and FKh010 alloys induced by an increase in the iron–carbon melt temperature from 1540 to 1560°C is caused by the transition of these ferroalloys from ultrahigh-melting to high-melting alloys. The lump sizes in the nitrided ferroalloys are found to affect their melting time: when the lump size increases eightfold (from 6 to 50 mm), the frozen solid steel skin thickness increases by a factor of 5–6 and the total melting time increases by a factor of 30. A nitrided FKhN10 ferroalloy has the best characteristics for processing steel due to its low melting point and the shortest melting time in an iron–carbon melt, which facilitates the assimilation of alloying elements by steel. [ABSTRACT FROM AUTHOR]

Experimental and industrial data are obtained about the heating rate and degree of Cr reduction for a vertical section of the workspace of an ore reduction electric furnace during treatment of a mixture of lean and rich chromium ores in relation to melting period. A scheme of proposed for the temperature fields and degree of chromium reduction in reaction zones of an ore reduction furnace using data about physicochemical characteristics of the ore raw material, determined under laboratory conditions. It is shown that the degree of Cr reduction in the lower levels of the furnace bath before tapping reaches 95%, and at the end of tapping it reaches up to 85%. [ABSTRACT FROM AUTHOR]

The reduction of the elements of the system containing (wt %): 40 Cr2O3, 21 FeO, 15 Al2O3, 6 SiO2, 16 MgO, 2 CaO, 0.006 P2O5 is subjected to thermodynamic simulation when the CaO content increases to a basicity of 3.15. Ferrosilicone (28% Fe, 65% Si; 7% Ni) is used as a reducer. For the simulation, the HSC Chemistry 6.12 software package developed by Outokumpu Research Oy (Finland) is used, and new thermodynamic constants for CrO and corrected constants for CaCr2O4 were introduced into its database. An increase in the reduction of chromium by 32.7% (from 64 to 95.1%) is found to occur when the slag basicity increases from 0.07 to 1.86. The rational slag basicity is 1.86–1.9. An increase in the reducer consumption from 0.5 to 1.05mred leads to an increase in the reduction of chromium by 52.4 to 95.1%. The chemical composition of the synthesized metal is (wt %) 50.4 Cr, 1.97 Si, 3.3 Ni, 0.21 Al, 0.0050 P, and Fe for balance. The simulation results can be used to calculate the reduction of the chromium ore elements using ferrosiliconickel. [ABSTRACT FROM AUTHOR]

Within ghost-free analytic perturbation theory (APT), devised in the last decade for low-energy QCD, simple approximations are proposed for three-loop analytic couplings and their effective powers, in both the spacelike (Euclidean) and timelike (Minkowskian) regions, accurate enough in a large range (1–100 GeV) of current physical interest. Effectiveness of the new model is illustrated by the example of γ(1 S) decay, where a standard analysis gives α s( M γ) = 0.170 ± 0.004, which is inconsistent with the bulk of data on α s. Instead, we obtain α ( M γ) = 0.185 ± 0.005, which corresponds to α ( M Z = 0.120 ± 0.002, which is close to the world-average value. The issue of scale uncertainty for γ decay is also discussed. [ABSTRACT FROM AUTHOR]

The rate of monopole decay into a dyon and an electron in an inhomogeneous external electric field is calculated by semiclassical methods. Comparison is made to an earlier result where this quantity was calculated for a constant field. Experimental and cosmological tests are suggested. [ABSTRACT FROM AUTHOR]