Ferrotitanium slag(FS)is a waste slag produced during the smelting of ferrotitanium alloys by thermite reduction.Its alumina content is high and can be used as alumina raw material.Iron runner castables containing dif...Ferrotitanium slag(FS)is a waste slag produced during the smelting of ferrotitanium alloys by thermite reduction.Its alumina content is high and can be used as alumina raw material.Iron runner castables containing different amounts of FS were prepared and characterized.The results show that the introduction of FS is beneficial to the sintering of the castables sample.When the FS concentration is 11.2 wt.%,the aggregate and matrix of the castables sample have a good combination,and the mechanical strength of the Al_(2)O_(3)–SiC–C castable reaches a maximum at room temperature.However,excessive introduction of FS generates a large amount of anorthite phase,which reduces the mechanical strength of the Al_(2)O_(3)–SiC–C castable at room temperature.In addition,the high-melting phase CaTiO_(3)is formed in FS,which has good mechanical properties.Meanwhile,the cracks of FS are reduced,and the combination between phases is closer,thus significantly improving the hot modulus of rupture of the castable.When the FS concentration is not above 33.6 wt.%,the castables show good slag resistance.The TiO_(2)in FS is transformed into TiC by carbothermal reaction,which is enriched at the boundary and prevents further reaction of the slag.展开更多
High ferrotitanium prepared directly by the thermite method has a disadvantageously high O content(≥10 wt%)because of the short slag-metal separation time.In this study,CaO and CaF2 are added to the melt to improve t...High ferrotitanium prepared directly by the thermite method has a disadvantageously high O content(≥10 wt%)because of the short slag-metal separation time.In this study,CaO and CaF2 are added to the melt to improve the basicity of the slag and melt separation under heat preservation is performed to strengthen slag-metal separation.The thermodynamics of the step-by-step reduction process of TiO2 in the Ti-Al-Fe-Si-O system whose composition is close to the alloy after melt separation were calculated.Samples of alloys and slags before and after melt separation were systematically analyzed.The result indicates that the reaction that TiO is reduced by Al to Ti is the limited step in the reduction process of TiO2.The O content of the alloys slightly decreases with temperature from 1873 to 2023 K,which agrees with the changes in the law of deoxidation limit.It is mainly attributed to the movement of chemical reactions in the alloy melt at different temperatures and slag-metal interfacial reaction.The addition of Al2 O3-CaO-CaF2 slag and high temperature promote the removal of Al2 O3 and titanium suboxides.The minimum contents of O and Al in the alloy reach 1.84 wt% and 3.26 wt%,respectively.展开更多
High ferrotitanium is used as a deoxidizer and alloying agent in steelmaking processes and is mainly produced using high-cost remelting processes.The thermite method is a simple and low-cost method for preparing low f...High ferrotitanium is used as a deoxidizer and alloying agent in steelmaking processes and is mainly produced using high-cost remelting processes.The thermite method is a simple and low-cost method for preparing low ferrotitanium.However,the high levels of S,Al,and O residues in the product severely restrict its applicability in the low-cost preparation of good-quality high ferrotitanium.In this study,a novel multistage deep reduction method for preparing high-quality high ferrotitanium is proposed,and the multistage desulfurization mechanism is systematically investigated.The results indicate that multistage desulfurization is an effective method for reducing the S content of high ferrotitanium prepared via the thermite method.During the strong desulfurization stage,Ti_(2)S reacts with CaO at the slag-metal interface and produces CaS.The S content decreases,while the O content increases,with the increase of CaO in the CaO-Al_(2)O_(3)-based slag.During the deep desulfurization,Ti_(2)S is deeply reduced by the Ca and produces CaS,thus further reducing the S content.The S content decreases with the incremental addition of Ca and can be reduced to 0.035 wt%after multistage desulfurization.展开更多
Ferrotitanium alloy polymer films, prepared by a simple technique of casting aqueous solutions of poly(vinyl alcohol) PVA containing ferrotitanium alloy on a horizontal glass plate, are useful as routine high-dose dos...Ferrotitanium alloy polymer films, prepared by a simple technique of casting aqueous solutions of poly(vinyl alcohol) PVA containing ferrotitanium alloy on a horizontal glass plate, are useful as routine high-dose dosimeters. These flexible plastic film dosimeters have pale yellow color, are bleached when exposed to gamma rays. The chemical composition of alloy was determined by EDX, and structure of alloy was determined by XRD. The response of these dosimeters depends on the concentration of alloy. The energy band gap Eg was calculated and the effect of gamma radiation on its value was determined. The optical absorption spectra showed that the absorption mechanism is an indirect allowed transition which found that energy band gap Eg decreases after irradiation. The response of these films has negligible humidity effects on the range of relative humidity from 0 to 100%. And also, it exhibits good preand post-irradiation stability in dark and light.展开更多
Development of metal matrix composite is becoming widespread in most engineering applications where excellent mechanical properties are required.Mechanical and microstructural properties of aluminium reinforced with s...Development of metal matrix composite is becoming widespread in most engineering applications where excellent mechanical properties are required.Mechanical and microstructural properties of aluminium reinforced with silicon carbide was investigated.Ingot of aluminium was melted in a furnace at temperature ranging between 650-700℃.Ferrotitanium and silicon carbide were preheated in a muffle furnace before addition to molten aluminium in a crucible furnace.Fixed proportions of magnesium,ferrotitanium and varying proportions of silicon carbide were utilized as reinforcements.Stirring was carried out manually for a minimum of 10 mins after the addition of each weight percent of silicon carbide.Resulting as-cast samples were sectioned for various mechanical and microstructural analysis.Microstructural studies from optical microscopy and scanning electron microscopy(SEM)showed the dispersion of reinforcements in the aluminium matrix.Mechanical properties which includes hardness and tensile strength of fabricated composites were observed to increase,while XRD analysis showed various phases formed from reaction between the matrix and reinforcements.展开更多
基金supported by the National Natural Science Foundation of China(52002295 and 52172023).
文摘Ferrotitanium slag(FS)is a waste slag produced during the smelting of ferrotitanium alloys by thermite reduction.Its alumina content is high and can be used as alumina raw material.Iron runner castables containing different amounts of FS were prepared and characterized.The results show that the introduction of FS is beneficial to the sintering of the castables sample.When the FS concentration is 11.2 wt.%,the aggregate and matrix of the castables sample have a good combination,and the mechanical strength of the Al_(2)O_(3)–SiC–C castable reaches a maximum at room temperature.However,excessive introduction of FS generates a large amount of anorthite phase,which reduces the mechanical strength of the Al_(2)O_(3)–SiC–C castable at room temperature.In addition,the high-melting phase CaTiO_(3)is formed in FS,which has good mechanical properties.Meanwhile,the cracks of FS are reduced,and the combination between phases is closer,thus significantly improving the hot modulus of rupture of the castable.When the FS concentration is not above 33.6 wt.%,the castables show good slag resistance.The TiO_(2)in FS is transformed into TiC by carbothermal reaction,which is enriched at the boundary and prevents further reaction of the slag.
基金financially supported by the National Natural Science Foundation of China (Nos. 51422403, 51774078 and U1508217)the Fundamental Research Funds for the Central Universities (No. N162505002)
文摘High ferrotitanium prepared directly by the thermite method has a disadvantageously high O content(≥10 wt%)because of the short slag-metal separation time.In this study,CaO and CaF2 are added to the melt to improve the basicity of the slag and melt separation under heat preservation is performed to strengthen slag-metal separation.The thermodynamics of the step-by-step reduction process of TiO2 in the Ti-Al-Fe-Si-O system whose composition is close to the alloy after melt separation were calculated.Samples of alloys and slags before and after melt separation were systematically analyzed.The result indicates that the reaction that TiO is reduced by Al to Ti is the limited step in the reduction process of TiO2.The O content of the alloys slightly decreases with temperature from 1873 to 2023 K,which agrees with the changes in the law of deoxidation limit.It is mainly attributed to the movement of chemical reactions in the alloy melt at different temperatures and slag-metal interfacial reaction.The addition of Al2 O3-CaO-CaF2 slag and high temperature promote the removal of Al2 O3 and titanium suboxides.The minimum contents of O and Al in the alloy reach 1.84 wt% and 3.26 wt%,respectively.
基金financially supported by the Technology Program of Henan Province(No.202102210207)the National Key Research and Development Plan(No.2017YFB0305401)+2 种基金the National Natural Science Foundation of China(Nos.51422403 and 51774078)the Fundamental Research Funds for the Central Universities(Nos.N162505002,N172506009 and N170908001)the Key Science and Shenyang Science and Technology Project(No.17-500-8-01)。
文摘High ferrotitanium is used as a deoxidizer and alloying agent in steelmaking processes and is mainly produced using high-cost remelting processes.The thermite method is a simple and low-cost method for preparing low ferrotitanium.However,the high levels of S,Al,and O residues in the product severely restrict its applicability in the low-cost preparation of good-quality high ferrotitanium.In this study,a novel multistage deep reduction method for preparing high-quality high ferrotitanium is proposed,and the multistage desulfurization mechanism is systematically investigated.The results indicate that multistage desulfurization is an effective method for reducing the S content of high ferrotitanium prepared via the thermite method.During the strong desulfurization stage,Ti_(2)S reacts with CaO at the slag-metal interface and produces CaS.The S content decreases,while the O content increases,with the increase of CaO in the CaO-Al_(2)O_(3)-based slag.During the deep desulfurization,Ti_(2)S is deeply reduced by the Ca and produces CaS,thus further reducing the S content.The S content decreases with the incremental addition of Ca and can be reduced to 0.035 wt%after multistage desulfurization.
文摘Ferrotitanium alloy polymer films, prepared by a simple technique of casting aqueous solutions of poly(vinyl alcohol) PVA containing ferrotitanium alloy on a horizontal glass plate, are useful as routine high-dose dosimeters. These flexible plastic film dosimeters have pale yellow color, are bleached when exposed to gamma rays. The chemical composition of alloy was determined by EDX, and structure of alloy was determined by XRD. The response of these dosimeters depends on the concentration of alloy. The energy band gap Eg was calculated and the effect of gamma radiation on its value was determined. The optical absorption spectra showed that the absorption mechanism is an indirect allowed transition which found that energy band gap Eg decreases after irradiation. The response of these films has negligible humidity effects on the range of relative humidity from 0 to 100%. And also, it exhibits good preand post-irradiation stability in dark and light.
文摘Development of metal matrix composite is becoming widespread in most engineering applications where excellent mechanical properties are required.Mechanical and microstructural properties of aluminium reinforced with silicon carbide was investigated.Ingot of aluminium was melted in a furnace at temperature ranging between 650-700℃.Ferrotitanium and silicon carbide were preheated in a muffle furnace before addition to molten aluminium in a crucible furnace.Fixed proportions of magnesium,ferrotitanium and varying proportions of silicon carbide were utilized as reinforcements.Stirring was carried out manually for a minimum of 10 mins after the addition of each weight percent of silicon carbide.Resulting as-cast samples were sectioned for various mechanical and microstructural analysis.Microstructural studies from optical microscopy and scanning electron microscopy(SEM)showed the dispersion of reinforcements in the aluminium matrix.Mechanical properties which includes hardness and tensile strength of fabricated composites were observed to increase,while XRD analysis showed various phases formed from reaction between the matrix and reinforcements.
