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Titanium or niobium alloying is done in microalloyed steels to improve the mechanical properties by grain refinement. Contrary to niobium, titanium addition gives additional advantages of 1) lower rolling load in the mill and 2) low ferroalloy cost. However, recovery of titanium, owing to its high affinity toward oxygen, is highly inconsistent and depends mainly on secondary steelmaking process parameters like dissolved oxygen content in steel, chemical composition of slag, addition method of alloy, fluid flow conditions of the bath during and after the addition of alloy and temperature of steel. Herein, process data have been analyzed and correlated to the chemical composition of steel and slag to understand the influence of various process parameters on titanium yield. Industrial plant trials have been conducted with a modified ferrotitanium (FeTi) addition practice. FeTi wire injection is done in seven heats with different wire injection speed and bottom argon purging rate. It has been found that 200 m min−1 of injection speed along with differential flow rate of argon from porous plugs with 35 and 6 Nm3 h−1, respectively, yields better recovery of titanium. The titanium recovery increases by 4% compared to the earlier practice of wire injection and argon purging. [ABSTRACT FROM AUTHOR]

Titanium oxide is a major component of bauxite residue (BR) with a high value, but it is often an unwanted element in common BR reuse options such as cement or iron production. Conventional carbothermic reduction smelting of BR produces a slag still containing a large amount of Ti. This study investigates an aluminothermic process for producing an FeTi alloy by combining BR, ilmenite ore, and fluxes. Based on thermodynamic calculations and batch experiments, the amounts of aluminum (reductant) and fluxes were investigated to achieve the optimum alloy production in parallel with a slag that could be further valorized in the cement industry. The mineralogical and chemical analysis of the metallic and slag phase agreed with the thermodynamic calculations. The results obtained by this study can lead to the development of a new process for the complete valorization of BR, paving the way for scaling up aluminothermic processes for producing ferroalloys from all iron-rich residues. [ABSTRACT FROM AUTHOR]

The article presents the description of slags produced by the Klyuchevskaya Concentrating Plant; samples of metallic chromium, ferrochrome, and ferrotitanium slag are described. In addition, the chemical composition of slag used for producing high-alumina refractory cement, physical and mechanical properties of cement obtained by remelting metallic chromium slags, and charge compositions during the remelting of metallic chromium slags are described. Finally, the scheme of covering the bottom of the dump truck body is discussed. [ABSTRACT FROM AUTHOR]

The suitability of the direct energy deposition process of exothermic powders Fe-Ti in joining dissimilar metals to produce small parts of a complete shape for various applications is considered. The procedure of the direct energy deposition of commercial pure iron and titanium in various proportions and the modes of the process are described. Optical microscopy and SEM with EDX analysis, X-ray analysis, and microhardness measurements of laser-fabricated intermetallics are applied. Intermetallic compounds of FeTi, Fe2Ti, eutectoids, complex titanium oxides and nitrides, and iron carbides are found. Interlayer and trans-layer cracks and pores are observed. A microhardness growth from 150 HV to 900 HV was obtained for all samples due to the precipitation of brittle intermetallic phases in the gradient Fe-Ti system during the DED. The dispersion of microhardness values becomes significant in Ti-rich areas; there, pores and cracks are found. The revealed structure features are considered in relation to published results and explained. Increased concentrations of Ti to Ti + Fe = 3:1 on the Fe- and Fe + Ti -substrate with concentrations of Ti + Fe = 1:1 and Ti + Fe = 1:3 lead to increasing hardness and its distribution, but also increases in residual microstress. Recommendations are given to reduce the power during the direct energy deposition of titanium layers and to apply Fe-substrate, which can reduce residual stress, pores, and cracks. [ABSTRACT FROM AUTHOR]

This research reports on the microstructural characterization and nanomechanical evaluation of hybrid aluminium-based composite, fabricated by reinforcing pure aluminium matrix with zirconia (ZrO2) and ferrotitanium (TiFe) particles. The composites were consolidated using the spark plasma sintering technique, and the properties of the reinforced composites were examined and compared with pure aluminium samples fabricated using the same sintering parameters. The formation of new phases in the hybrid composites was ascertained using the X-ray diffraction technique, while the morphologies of the starting powders and as-sintered specimens were analysed using optical and scanning electron microscopes. Mechanical tests such as Vickers microhardness and frictional coefficient were determined to ascertain the respective strength and tribological performance. Nanoindentation test was also carried out to evaluate the nanomechanical properties such as penetration depth, elastic modulus, work indentation, and indentation creep. The results from this study revealed that mixing and sintering the admixed powders at sufficiently high temperature resulted in the formation of new phases which contributed to improved mechanical performance of the hybrid composites. The absence of pinning effect in loading and unloading curves from the nanoindentation test conducted confirmed the homogeneous dispersion of the reinforcement particles. Overall, the sample reinforced with 5% TiFe and 5% ZrO2 exhibited the most improved mechanical properties, while the unreinforced aluminium sample recorded the least mechanical and nanomechanical performance. [ABSTRACT FROM AUTHOR]

Titanium oxide is a major component of bauxite residue (BR) with a high value, but it is often an unwanted element in common BR reuse options such as cement or iron production. Conventional carbothermic reduction smelting of BR produces a slag still containing a large amount of Ti. This study investigates an aluminothermic process for producing an FeTi alloy by combining BR, ilmenite ore, and fluxes. Based on thermodynamic calculations and batch experiments, the amounts of aluminum (reductant) and fluxes were investigated to achieve the optimum alloy production in parallel with a slag that could be further valorized in the cement industry. The mineralogical and chemical analysis of the metallic and slag phase agreed with the thermodynamic calculations. The results obtained by this study can lead to the development of a new process for the complete valorization of BR, paving the way for scaling up aluminothermic processes for producing ferroalloys from all iron-rich residues.

The suitability of the direct energy deposition process of exothermic powders Fe-Ti in joining dissimilar metals to produce small parts of a complete shape for various applications is considered. The procedure of the direct energy deposition of commercial pure iron and titanium in various proportions and the modes of the process are described. Optical microscopy and SEM with EDX analysis, X-ray analysis, and microhardness measurements of laser-fabricated intermetallics are applied. Intermetallic compounds of FeTi, Fe2Ti, eutectoids, complex titanium oxides and nitrides, and iron carbides are found. Interlayer and trans-layer cracks and pores are observed. A microhardness growth from 150 HV to 900 HV was obtained for all samples due to the precipitation of brittle intermetallic phases in the gradient Fe-Ti system during the DED. The dispersion of microhardness values becomes significant in Ti-rich areas; there, pores and cracks are found. The revealed structure features are considered in relation to published results and explained. Increased concentrations of Ti to Ti + Fe = 3:1 on the Fe- and Fe + Ti -substrate with concentrations of Ti + Fe = 1:1 and Ti + Fe = 1:3 lead to increasing hardness and its distribution, but also increases in residual microstress. Recommendations are given to reduce the power during the direct energy deposition of titanium layers and to apply Fe-substrate, which can reduce residual stress, pores, and cracks.

Due to the increasing demand for lighter materials with enhanced properties, the upgrade of techniques to improve the production of high-performance composite materials is of great interest in modern technology. The microstructural and mechanical properties of spark plasma sintered aluminium based composites with ferrotitanium (TiFe) and silicon carbide (SiC) reinforcements were investigated. High energy ball milling technique was adopted to effectively disperse the particles SiC and TiFe reinforcements into the matrix of aluminium, and the admixed powders were compacted using spark plasma sintering technique. The specimens sectioned from the sintered compacts were analysed using an X-ray diffractometer (XRD), optical microscope (OM), and field emission scanning electron microscope (FESEM) to understand the microstructural features and phase evolution of the sintered composites. The mechanical properties of the composites were also investigated through hardness, nanomechanical and tribology tests. Results from the microstructural examinations conducted shows that the reinforcement particles were evenly dispersed within the aluminium matrix, as a result of the milling process. Furthermore, all the sintered composites had their microstructural features enhanced, but properties such as hardness, frictional coefficient, and elastic modulus were more enhanced in specimen reinforced with 2%SiC+2%TiFe particles. The reduced crystallite size recorded by the sintered specimens confirmed the effectiveness of the milling process, and powder metallurgy route adopted for fabrication.

Possibilities are considered of processing titanium and titanium wastes under the conditions of plasma-arc remelting into a through crucible in the form of sublimates, which formed in electron beam furnaces and gate systems from VT5 type alloy, produced in vacuum induction furnaces. Possibilities of plasma-arc skull melting at processing these wastes into small ingots and 70 % ferrotitanium were studied. Hydrogen behaviour in furnace atmosphere at remelting of the above-mentioned wastes was investigated. It is shown that under the conditions of plasma-arc remelting it is possible to process titanium and titanium alloy wastes into billets for further remelting, castings and ferrotitanium. Ref. 9, Tabl. 3, Fig. 7. [ABSTRACT FROM AUTHOR]

The use of aluminium based composite is becoming widespread in the industries where enhanced mechanical and improved corrosion resistance properties are required. Microstructural analysis, hardness and corrosion properties of aluminium based composites reinforced with particles of silicon carbide (SiC) and ferrotitanium (TiFe) were investigated. The composites were produced using stir casting technique, with the dispersion of different weight percentages of single and dual reinforced particles within the aluminium matrix. The microstructural evolution, microhardness and nanohardness properties of the as-cast specimens were investigated. Electrochemical testing of specimens was carried out using potentiodynamic polarization and potentiostatic techniques in 3.5 wt.% sodium chloride (NaCl) solution. The microstructural examinations conducted showed a homogeneous dispersion of the SiC and TiFe reinforcements within the aluminium matrix. The hardness (micro and nano) properties of the reinforced specimens were enhanced due factors which include effective load transfer mechanism between the reinforcements and matrix, and an impediment to dislocation movement within the composite. The specimens reinforced with particles of 5% SiC +2% TiFe and 5% SiC exhibited the most improved corrosion resistance from the potentiodynamic polarization and potentiostatic tests conducted. This was confirmed by the surface analysis of corroded specimens carried out using a field emission scanning electron microscope (FE-SEM). The formation of filiform structure on the surface of the unreinforced aluminium alloy and several pits on the surface of the composites was attributed to the aggressive effect of the chloride ions present in the test electrolyte. [ABSTRACT FROM AUTHOR]

The most appropriate electrolytes for the electrochemical manufacturing of ferrotitanium are examined. The electrochemical production of ferrotitanium is experimentally studied. An electrolyzer scheme is presented. [ABSTRACT FROM AUTHOR]

Aluminium matrix composites have been developed to replace other conventional engineering materials in specific industries where enhanced properties are required. The corrosion susceptibility of sintered unreinforced aluminium and composites in chloride medium (AMCs) were studied. The powders of pure as-received aluminium (matrix) and particles of ferrotitanium and silicon carbide particles were homogeneously dispersed using ball milling technique. Powder metallurgy route was utilised for consolidating the milled powders into a sintered compact. Microstructural examination of the compacted pure aluminium and composites confirmed an even distribution of the reinforcements in the aluminium matrix. The produced composites also recorded an improved corrosion resistance in a corrosive medium of 3.5 wt.% laboratory prepared sodium chloride, from the potentiodynamic polarization and chronoamperometry (potentiostatic) tests. The corroded specimens were further assessed for pitting using a field emission scanning electron microscope (FE-SEM). The resistance of the fabricated samples to corrosion was improved upon the addition of TiFe and SiC reinforcements. [ABSTRACT FROM AUTHOR]

A set of ICP-AES techniques has been developed for determination of rated elements: Ti, Si, P, Al, Cu, Mo, V, Sn, and Zr in ferrotitanium; Ni, Fe, Cu, Co, and As in ferronickel; Si, Cr, and P in ferrochrome silicon; Zr, Si, Al, P, and Cu in zirconium ferrosilicon; Mn, Si, and P in manganese ferrosilicon. Combination of the multielement ICP-AES method which allows precise determination of the elements in ferroalloys in a wide range of concentrations and the microwave preparation of samples in closed autoclaves which excludes the loss of the components to be determined provides the rapidity of the analysis procedure. The composition of solutions for opening samples of ferroalloys and the temperature–time modes of microwave sample preparation in an autoclave are substantiated. Conditions for ICP-AES determination of the rated elements in ferroalloys are studied. Analytical lines of the elements to be determined free from significant spectral overlaps are chosen. The dilution rates of the solutions are determined. The method of internal standard was used to improve the reproducibility of the analytical signal for Ti determination in ferrotitanium, Si and Cr in ferrochrome silicon, and all rated elements in manganese ferrosilicon and ferronickel. The spectrometer was calibrated using model solutions and solutions of standard samples with additions of the certified solutions of the elements to be determined. To determine Ti, Si, P, Al, Cu, V, and Zr in ferrotitanium; Ni, Fe, Cu, and Co in ferronickel; Si, Cr, and P in ferrochrome silicon; Zr, Si, Al, P, and Cu in zirconium ferrosilicon; Si and P in manganese ferrosilicon, a multidimensional graduation by two analytical lines was used. The correctness of the determination was evaluated in analysis of standard samples of ferroalloys and comparative analysis of the obtained results with the data of standard methods: comparison of the variances according to the Fisher criterion did not reveal any significant difference between them, whereas the use of the modified Student test showed the absence of a systematic error. [ABSTRACT FROM AUTHOR]

Combustion of FTi70 industrial ferrotitanium containing 65.9% Ti and a model alloy of iron with 30.6% Ti in nitrogen is described. It is shown that the degree of nitriding of the combustion products of industrial ferrotitanium is low. The distribution of nitrogen along the sample diameter is uneven. The dilution of the alloy with the final product increases in the degree of nitriding. The study of the combustion of the model alloy concludes that the degree of nitriding increases along with the melting point of the initial alloy. The composition of the combustion products of ferrotitanium is described. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the synthesis, characterization and mechanical properties of aluminium reinforced with ferrotitanium and silicon carbide via stir casting technique. Microstructures of as-cast samples were analysed using optical and scanning electron microscopes equipped with energy-dispersive X-ray spectroscopy. The mechanical properties in terms of hardness, tensile, tribological behaviour and fracture were assessed. Results showed that the homogeneous dispersion of reinforcement was within the metal matrix composite. Tribological study revealed a decrease in frictional coefficient of the composites with lowest frictional coefficient observed in composite with addition of silicon carbide as reinforcement. Morphology of fractured surface displayed a reduction in the size of dimples formed in reinforced aluminium composites when compared with larger dimple sizes observed in as-cast aluminium alloy. [ABSTRACT FROM AUTHOR]

Abstract The adiabatic temperatures and equilibrium phases in the FeTiO 3 - α Mg-C(B, Si)- k NaCl system (where α = 0.2–15, k = 0–3) were analyzed to predict the formation of fine powders of titanium compounds from natural ilmenite sand. From the parametric study, the critical variables were identified and optimized for the synthesis of FeTi, TiC, TiB 2 , and TiFeSi 2 under a combustion regime. The experimentally measured temperatures were in good agreement with those predicted from thermochemical calculations in the 900–1800 °C range. The purified products were characterized using X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The fine powders of titanium compounds were mainly single phase with a purity of at least 95 wt%. Considering the various stages of the synthetic process, a mechanism is proposed to explain how the process of ilmenite recovery occurred. Graphical abstract Image Highlights • Natural ilmenite was used as a precursor for synthesizing Ti compounds. • Combustion temperatures and phases were determined in FeTiO 3 -αMg-C(B, Si)- k NaCl system. • The effect of Mg and NaCl concentration on the combustion temperature was revealed. • The ilmenite was converted into FeTi, TiC, TiB 2, and FeTiSi 2 fine powders. • A reduction pathway in the synthesis of Ti compounds was proposed. [ABSTRACT FROM AUTHOR]

Effect of reaction heat per unit mass on the ferrotitanium prepared by thermite method was studied. The samples were analyzed by scanning electron microscope, energy spectrum analyzer, oxygen/nitrogen/hydrogen analyzer and inductively coupled plasma emission spectrometer. The results indicate that the burn rate of the ingredients gradually increases with the increasing reaction heat per unit mass, while it decreases with the increasing Ti content of the objective ferrotitanium. Meanwhile, when the reaction heat per unit mass increases, the Al and O contents of the alloy decrease. A higher reaction heat per unit mass is beneficial to the removal of Al2 O3 inclusion because of a better slag-metal separation. Nevertheless, under the same reaction heat, the effect of slag-metal separation goes worse and Al and O contents increase with the increasing Ti content of the objective ferrotitanium. Reaction heat per unit mass has a greater effect on the burn rate, slag-metal separation and the recovery of objective ferrotitanium with high Ti content. [ABSTRACT FROM AUTHOR]

The aluminothermic process is used for producing ferrotitanium alloy (FeTi) from an ilmenite concentrate. In this study, based on thermodynamic calculations and experiments, we investigated the effects of adding varying amounts of exothermal agent (NaClO3), slag-forming agent (CaO), and reducing agent (Al) on the recovery ratio of Ti in the aluminothermic process. The thermodynamic calculations suggested that the exothermal agent plays a crucial role in producing the FeTi alloy from the ilmenite concentrate and the maximum Ti grade in the FeTi alloy was approximately 30 wt %. Experimentally, it was verified that the FeTi alloy obtained under the optimum mixing conditions contained 30.2–30.8 wt % Ti, 1.1–1.3 wt % Si, 9.5–11.2 wt % Al, and 56.9–58.0 wt % Fe, along with trace impurities and small amounts of gases such as oxygen (0.35–0.66 wt %) and nitrogen (0.01–0.02 wt %). At the optimum mixing conditions, the recovery ratio of Ti into the obtained FeTi alloy phase was 60.6–68.9%. These results matched closely with the thermodynamic calculations. Therefore, the thermodynamic calculations performed herein are expected to significantly contribute toward the development of new processes and improvement in conventional processes for producing various ferroalloys including the FeTi alloy through the aluminothermic process.

This paper presents a promising way to decrease the working temperature during the electrolysis of solid ilmenite to produce submicron ferrotitanium powders by selecting equimolar CaCl 2 -NaCl instead of pure CaCl 2 as the electrolyte. The results imply that when ilmenite is electrolysed in equimolar CaCl 2 -NaCl melts at a lower temperature of 700 °C, porous ferrotitanium powders with homogeneous 2.1-μm particles are produced. The particle size is found to increase with the increase in temperature. However, much more energy is consumed at elevated temperatures. Electrolysis using pure NaCl, CaCl 2 -NaCl in molar ratios of 0.5:1 and 1:1 and pure CaCl 2 melts shows the unique influence of CaCl 2 on the reduction process. The results demonstrate that ilmenite can only be reduced to Fe and TiO 0.997 in pure NaCl electrolyte, but ferrotitanium is successfully produced in porous structures when mixed eutectic CaCl 2 -NaCl melts are chosen as electrolytes. The production of ferrotitanium is also found to increase with increasing concentration of CaCl 2 . [ABSTRACT FROM AUTHOR]

The effect of ilmenite with different reduction degrees on the production of ferrotitanium, using a self-propagation high-temperature synthesis method with aluminum as the reducing agent, was investigated. Increasing the degree of reduction not only contributed to lower consumption of aluminum, but also lowered the oxygen content and improved the grades of titanium and iron in the ferrotitanium. The aluminum content of the ferrotitanium increased with an increase in the extent of reduction of ilmenite, so the Al2O3 content formed in the slag decreased with the constant addition of CaO and CaF2 to the Al powder. This decreased relatively the content of high-melting-point CaAl12O19 and increased the contents of low-melting-point CaAl2O4 and CaF2 in the slag, thereby promoting the separation of ferrotitanium and slag. Improving the reduction degree of ilmenite is beneficial to the preparation of ferrotitanium.

Research is carried out for preparation of ferrosilicotitanium by self-propagating high-temperature synthesis (SHS) using ferroalloy powders as starting materials. On the basis of data obtained, industrial technology is developed and assimilated for producing ferrosilicotitanium for alloying pipe steels instead of a high percentage ferrotitanium. An industrial test batch is prepared and tests are carried out successfully under Magnitogorsk Metallurgical Combine conditions. [ABSTRACT FROM AUTHOR]

Ferro-titanium (FeTi) alloy was prepared successfully from synthesized ilmenite through electrochemical reduction method in equal-molar CaCl 2 NaCl molten salt at 973 K and a cell voltage of 3.2 V under inert atmosphere, where molybdenum rod and graphite were used as cathode and anode respectively. It is indicated that the CaO content in the molten salt has an appreciable effect on the phase transformation of reactants occurring in the electrolytic process. The optimized CaO content in the molten salt is 1 mol% and this suitable content of CaO can significantly improve the reduction rate of ilmenite. The micromorphology of the ferrotitanium product is porous with the amount of 1 mol%CaO addition. It is observed that the particles of ferrotitanium had a uniform size in the initial period of time. Along with the electrolysis time extension, however, the particles connected with each other to generate strips and then form a honeycomb structure. These findings provide a basis for scientifically discussion on the optimization of CaO addition amount during the electrochemical reduction of ilmenite and other oxides in molten salts. [ABSTRACT FROM AUTHOR]