Reoxidation of Aluminum in Fe-Al-M (M = C,Mn, and Ti) melts with CaO-Al2 O3-Fe t O (3 mass pct) slags

An Fe-0.01 to 0.5 mass pctAl alloy and an Fe-0.003 to 0.71 mass pctAl-1 mass pctM (M = C, Mn, and Ti) alloy were reoxidized with the CaO-Al₂O₃-Fe_tO (3 mass pct) slags at 1873 K in an Al2O3 or CaO crucible for 5 and 60 minutes. The contents of acid-insoluble Al, total O, and alloying element M in metal as well as those of M and FetO in slag were measured as a function of total Al content. On the basis of the present and previous results for Fe-Al-Te alloys, the effect of alloying elements on the degree of supersaturation with respect to the Al2O3 precipitation was studied. As a result, the supersaturation phenomenon was observed in all experiments at 5 minutes, but in the experiments at 60 minutes, it was observed only in Fe-Al and Fe-Al-Ti alloys. No supersaturation was observed in the reoxidation of Si in Fe-0.13 to 0.98 mass pctSi alloys with the CaO-SiO2-FetO (3 mass pct) slags in a CaO crucible at 5 and 60 minutes.     

Analysis of size distributions of primary oxide inclusions in Fe-10 mass Pct Ni-M (M=Si, Ti, Al, Zr, and Ce) alloy

The planar and spatial size distributions of primary oxide inclusions were measured in an Fe-10 mass pct Ni alloy on deoxidation with 0.2 mass pct M (M=Si, Ti, Al, Zr, and Ce). It was found that the size distribution of inclusions obtained at a certain magnification in microanalysis was accurate only in a limited range of particle size, due to the limit of observation for the minimum size and observed area. The inclusion characteristics such as mean spatial diameter, , the number of particles per unit volume, N _v, and the volume fraction of particles, f _v, were estimated from the size distribution obtained in a planar cross section by using different methods. The and N _v values and the size distribution estimated from the cross-sectional method using different magnifications were compared with those obtained from the extraction method. The f _v values obtained from size distribution were found to be considerably greater than those from chemical analysis of oxygen or metal element as inclusion. Furthermore, the behavior of the size distribution as a function of holding time at 1873 K is discussed.     

LaNi4Al0.75M0.25(M=Mn,Sn,In,Ti,Zr)合金吸放氢性能研究

采用XRD及等容法研究了元素替代对LaNi4Al0.75M0.25（M=Mn,Sn,In,Ti,Zr）合金相结构、吸放氢动力学和热力学性能的影响。结果表明：Sn,In替代对合金的吸放氢平台压力影响不大,而Mn,Ti,Zr替代明显降低了合金的平台压力;5种合金的吸氢量按替代元素Mn〉In〉Sn〉Ti〉Zr顺序降低,XRD分析结果表明降低原因是元素替代后合金中形成了杂质相;合金主相的晶胞体积与热力学焓变ΔH的绝对值大小顺序按替代元素表示均为Mn〉Zr〉Ti〉Sn〉In,而熵变ΔS差异不大。     

Effect of Metal Oxide Doping into Ce0.5Zr0.5O2 on Catalytic Activity of MnOx/γ-Al2O3/Ce0.45Zr0.45M0.1Ox(M=Y, La, Mn) Honeycomb Catalysts

This article showed that the catalytic activity of MnOx/γ-Al2O3/Ce0.5Zr0.5O2 monolithic catalyst toward the catalytic combustion of ethanol in a fixed bed reactor could be greatly improved by doping three metal oxides into Ce0.5Zr0.5O2. The catalytic activity of MnOx/γ-Al2O3/Ce0.45Zr0.45M0.1Ox (M=Y, La, Mn) is better than that of MnOx/γ-Al2O3/Ce0.5Zr0.5O2. The order of activity of the catalysts is as follows: MnOx/γ-Al2O3/Ce0.45Zr0.45Y0.1Ox＞MnOx/γ-Al2O3/Ce0.45Zr0.45La0.1Ox＞MnOx/γ-Al2O3/Ce0.45Zr0.45Mn0.1Ox＞MnOx/γ-Al2O3/Ce0.5Zr0.5O2. The influence of the loading amount of manganese oxide in enhancing the catalytic activity of MnOx/γ-Al2O3/Ce0.45Zr0.45Y0.1Ox was investigated. The results showed that when MnO2 loading amount was 10%(mass fraction), the MnOx/Al2O3/Ce0.45Zr0.45Y0.1Ox catalyst recorded the highest activity.     

Structure and Redox Properties of VCe0.95M0.05（M=Cu,Co,Mn,Fe and Cr）Mixed Oxides

Ｖａｎａｄｉｕｍｏｘｉｄｅｈａｓｂｅｅｎｗｉｄｅｌｙｓｔｕｄｉｅｄｉｎｔｈｅｒｅｃｅｎｔｙｅａｒｓｂｅｃａｕｓｅｏｆｉｔｓｉｍｐｏｒｔａｎｃｅｉｎｍａｎｙａｒｅａｓｏｆｃｈｅｍｉｓｔｒｙ .Ｉｎｔｈｅａｒｅａｏｆｃａｔａｌｙ ｓｉｓ ,ｖａｎａｄｉｕｍｏｘｉｄｅｈａｓｂｅｅｎｕｓｅｄａｓａｃａｔａ ｌｙｓｔｆｏｒｓｅｌｅｃｔｉｖｅｏｘｉｄａｔｉｏｎ ,ｏｘｉｄａｔｉｖｅｄｅｈｙｄｒｏ ｇｅｎａｔｉｏｎ ,ａｎｄａｍｍｏｘｉｄａｔｉｏｎｒｅａｃｔｉｏｎ[1～ 4] .Ｉｎｔｈｅｏｘｉｄａｔｉｏｎｒｅａｃｔｉｏｎｏｎ…     

Sol-Gel Synthesis of LaMO3 (M = Cr, Mn, Fe, Co, Ni) Nanocrystalline Powders

Sol-gel synthesis of LaMO3 ( M = Cr, Mn, Fe, Co, Ni) nanocrystalline Powders was investigated. DSC measurement shows that precursors decomposed at about 403 K and 620 K to bum out of N, C, and H. The calcined samples at 1073 K were determined by XRD to be single phase. SEM observation shows that the prepared samples are nanocrystalline powders in broad sense. The average grain size of LaM'O3 (M'= Cr, Mn, Fe, Ni) is 150 ～700 nm,and the grain size of LaCoO3 is about 30 nm.     

Effects of different alloying elements M (M =Fe,Ni,Mn,Si,Mo,Cu,Y)on Cr2O3 with Cl:a first-principles study

Using the first-principles methods,the effects of different alloying elements M (M =Fe,Ni,Mn,Si,Mo,Cu,Y) on Cr2O3 with C1 adsorption are studied.The results sho...     

时效转变与Ti/(Ti,Zr)2Si复合材料的制备

通过真空自耗电极炉熔炼得到硅锆比为1，2的Ti—Zr—Si合金材料，对合金材料进行了1200℃，3．5h的固溶处理和850℃不同时间的时效处理，通过时效析出反应制备Ti／(Ti，Zr）2Si复合材料。利用光学显微镜、扫描电镜、X射线衍射、EDX分析了Ti—Zr—Si合金的铸造、固溶和不同时效阶段的显微组织及其相组成。分析结果表明，硅锆比为1／2(重量百分比)的Ti—Zr—Si合金，铸造组织为块状β—Ti、晶界由块状β—Ti和条状的5—3型硅化物组成；Ti—Zr—Si合金经过850℃，480min的时效处理，5—3型硅化物转变为2—1型硅化物；尺寸细小、分布均匀的2—1型硅化物使制备高性能的Ti／(Ti，Zr)2Si复合材料成为可能。     

Effects of MO_x(M=Mn,Cu,Sb,La)on V-Mo-Ce/Ti selective catalytic reduction catalysts

A series of MO_x-V_2O_5-MoO_3-CeO_2/TiO_2(M=Mn,Cu,Sb,and La) catalysts were prepared via an impregnation method.The physico-chemical properties of the catalysts were characterized and their NH_3-SCR of NO performance was compared.The Mn-loaded catalyst(Mn5V1Mo3Ce7/Ti) exhibits a large number of acid sites of varying strength,and together with good reducibility of the catalyst,contributes to the optimal SCR performance.The sulphate species formed in the presence of SO_2 significantly enhance the H_2O and SO_2 tolerance of Mn5V1Mo3Ce7/Ti.The Cu-loaded catalyst(Cu5V1Mo3Ce7/Ti)demonstrates potential in flue gas applications in the absence of SO_2 at low temperatures because of the excellent redox ability observed and the high degree of weak acid sites.The Sb and La loaded catalysts(Sb5V1Mo3Ce7/Ti and La5V1Mo3Ce7/Ti),especially La5V1Mo3 Ce7/Ti,exhibit the largest number of acid sites and the lowest reducibility,and therefore,may be suitable for use in high temperature denitrification applications.     

Structure formation in binary Al-TM (TM = Mn,Co, Ni,Cu) melts

The structures of binary Al-TM (transition metal TM = Mn, Co, Ni, Cu) melts at near-liquidus temperatures are studied by X-ray diffraction and simulation using the reverse Monte Carlo method. The melts are found to have chemical local atomic ordering, and this ordering depends on the nature and content of TM. Chemical local atomic ordering leads to a medium-range order as a result of TM atom localization at distances of 0.4–0.5 nm in the composition of polytetrahedral clusters having icosahedral symmetry. A medium-range order in the melts is identified due to the presence of an additional maximum (prepeak) in the left slope of the first peak in experimental structure factor curves. The local atomic orders in the melts and the corresponding crystalline and quasicrystalline phases are found to correlate with each other.