摘要:
This invention relates to a magnesium alloy comprising: (a) 1.32-1.8 w1% Gd, (b) 2-3.6 w1% Nd, (c) 0.55-0.7 w1% Zr, (d) 0.20-0.40 w1% Zn, and (d) at least 85 wi % Mg, wherein the ratio of Gd:Nd (wt %) is 0.40-0.63. The invention also relates to an aircraft component comprising the magnesium alloy, as well as a to a method for producing the magnesium alloy.
摘要:
This invention relates to an aqueous dispersion of particles, the dispersion having a particle content of 10-70 wt %, and the particles comprising, on an oxide basis: (a) 10-98 wt % in total of ZrO2+HfO2, and (b) 2-90 wt % in total of Al2O3, CeO2, La2O3, Nd2O3, Pr6O11, Y2O3, or a transition metal oxide, wherein the dispersion has a Z-average particle size of 100-350 nm and the particles have a crystallite size of 1-9 nm. The invention also relates to a substrate coated with the aqueous dispersion of particles.
摘要:
A composition based on cerium, zirconium and tungsten is described. The composition has a content expressed as an oxide, of which cerium is from 5% to 30% of the composition, tungsten is from 2% to 17% of the composition, and the remainder of the composition is zirconium. After aging at 750° C. under an air atmosphere including 10% water, it has a two-phase crystallographic structure having a tetragonal zirconia phase and a monoclinic zirconia phase, with no presence of a crystalline phase including tungsten. The composition can be used as a catalyst, especially in an SCR process.
摘要:
The present invention relates to oxygen storage components for catalytic converters for automobile exhaust systems, particularly for those with petrol-driven engines. In accordance with the present invention there is provided a ceria containing mixed oxide suitable as an oxygen storage material having a ceria content in the range 10 to 80% by weight and at least one metal oxide in an amount of less than 0.5% by weight, wherein the metal is selected from the first row transition elements and the group IVB elements of the periodic table. The inventions also provides an oxygen storage material for catalytic converters for automobile exhaust systems comprising an oxide of the present invention.
摘要:
An improved method for the formation of composite hydroxides or oxides comprising, on an oxide basis, Al2O3 and ZrO2, and optionally CeO2, La2O3, Nd2O3, Pr6O11, Sm2O3, Y2O3, and other rare earth oxides, comprising the steps of preparing an aqueous metal salt solution and forming a hydroxide precipitate slurry by combining the aqueous metal salt solution with an aqueous solution of a caustic alkali at a pH greater than 8.5 to precipitate out all the metal species. The variation in pH during the precipitation reaction is ±1. The invention also relates to composites formed by this method comprising 20-70 wt % Al2O3, 10-77 wt % ZrO2, 0-34 wt % CeO2 and 0-22 wt % REOs other than CeO2, and to composites per se comprising, on an oxide basis, 42-70 wt % Al2O3, 10-48 wt % ZrO2, 2-34 wt % CeO2 and 0-9 wt % REOs other than CeO2 and having the following properties after heating to 850° C. over four hours and holding at 850° C. for four hours then allowing to cool to ambient temperature:—a surface area after aging at 950° C. for 2 hours equal to or greater than 60 m2/g, and—a surface area after aging at 1100° C. for 2 hours equal to or greater than 30 m2/g.
摘要翻译:一种用于形成复合氢氧化物或氧化物的改进方法,其包含以氧化物为基准的Al 2 O 3和ZrO 2以及任选的CeO 2,La 2 O 3,Nd 2 O 3,Pr 6 O 11,Sm 2 O 3,Y 2 O 3和其它稀土氧化物,包括以下步骤: 盐溶液,并通过将金属盐水溶液与pH大于8.5的苛性碱水溶液组合形成氢氧化物沉淀物浆料,以沉淀所有金属物质。 沉淀反应中pH值的变化为±1。 本发明还涉及通过该方法形成的复合材料,其包含20-70重量%的Al 2 O 3,10-77重量%的ZrO 2,0-34重量%的CeO 2和除CeO 2之外的0-22重量%的REO,以及本身的复合材料本身包括 氧化物基,42-70重量%的Al 2 O 3,10-48重量%的ZrO 2,2-34重量%的CeO 2和0-9重量%的除CeO 2之外的REO,并且在四小时内加热至850℃后具有以下特性; 在850℃下保持4小时,然后冷却至环境温度: - 在950℃老化2小时以上等于或大于60m 2 / g的表面积,和在1100℃老化后的表面积 ℃2小时等于或大于30m 2 / g。
摘要:
An improved method for the formation of composite hydroxides or oxides comprising, on an oxide basis, Al2O3 and ZrO2, and optionally CeO2, La2O3, Nd2O3, Pr6O11, Sm2O3, Y2O3, and other rare earth oxides, comprising the steps of preparing an aqueous metal salt solution and forming a hydroxide precipitate slurry by combining the aqueous metal salt solution with an aqueous solution of a caustic alkali at a pH greater than 8.5 to precipitate out all the metal species. The variation in pH during the precipitation reaction is ±1. The invention also relates to composites formed by this method comprising 20-70 wt % Al2O3, 10-77 wt % ZrO2, 0-34 wt % CeO2 and 0-22 wt % REOs other than CeO2, and to composites per se comprising, on an oxide basis, 42-70 wt % Al2O3, 10-48 wt % ZrO2, 2-34 wt % CeO2 and 0-9 wt % REOs other than CeO2 and having the following properties after heating to 850° C. over four hours and holding at 850° C. for four hours then allowing to cool to ambient temperature: —a surface area after aging at 950° C. for 2 hours equal to or greater than 60 m2/g, and —a surface area after aging at 1100° C. for 2 hours equal to or greater than 30 m2/g.
摘要翻译:一种用于形成复合氢氧化物或氧化物的改进方法,其包含以氧化物为基准的Al 2 O 3和ZrO 2以及任选的CeO 2,La 2 O 3,Nd 2 O 3,Pr 6 O 11,Sm 2 O 3,Y 2 O 3和其它稀土氧化物,包括以下步骤: 盐溶液,并通过将金属盐水溶液与pH大于8.5的苛性碱水溶液组合形成氢氧化物沉淀物浆料,以沉淀所有金属物质。 沉淀反应中pH值的变化为±1。 本发明还涉及通过该方法形成的复合材料,其包含20-70重量%的Al 2 O 3,10-77重量%的ZrO 2,0-34重量%的CeO 2和除CeO 2之外的0-22重量%的REO,以及本身的复合材料本身包括 氧化物基,42-70重量%的Al 2 O 3,10-48重量%的ZrO 2,2-34重量%的CeO 2和0-9重量%的除CeO 2之外的REO,并且在四小时内加热至850℃后具有以下特性; 在850℃下保持4小时,然后冷却至环境温度: - 在950℃老化2小时之后的表面积等于或大于60m 2 / g, - 在1100℃老化后的表面积 ℃2小时等于或大于30m 2 / g。
摘要:
This invention relates to an improved amorphous zirconium hydroxide and a method for its production. The hydroxide has a surface area of at least 300 m2/g, a total pore volume of at least 0.70 cm3/g and an average pore size of between 5 nm and 15 nm, and is prepared by a process which comprises the steps of: a) preparing an aqueous solution comprising sulphate anions and a zirconium salt such that the ZrO2:SO3 ratio is 1:0.40 to 1:0.52, (b) chilling the solution to below 25° C., (c) adding an alkali in order to precipitate the amorphous zirconium hydroxide, (d) filtering and washing the precipitated zirconium hydroxide with water or an alkali to remove residual sulphate and chloride, (e) hydrothermally treating the zirconium hydroxide at a pressure of less than 3 barg, and (f) drying the zirconium hydroxide. The zirconium hydroxide of the present invention, which can be doped, is particularly useful in catalytic applications.
摘要:
A process is disclosed for the preparation of lithium zirconate and doped lithium zirconates for use as regenerable carbon dioxide sorbants by wet mixing zirconium hydroxide with lithium carbonate and then calcining the mixture. Due to the improved physical properties resulting from the disclosed preparation process, the lithium zirconates produced by this process are capable of absorbing carbon dioxide at high rates and in large amounts.
摘要:
An additive for a ferrous melt to remove sulphur comprises agglomerates of a mixture of from 15 to 50% by weight of magnesium, 1 to 10% by weight of calcium fluoride and a refractory material to form a metal-permeable matrix when subjected to the temperature of a ferrous melt. The agglomerates may contain a binder and be formed into briquettes. The additive may be introduced into the melt by plunging.
摘要:
Magnesium alloys are treated in a hydrogen atmosphere containing water vapor at an elevated temperature to enable hydrogen to diffuse into the alloy surface, the proportion of water vapor in the atmosphere being reduced during exposure. The alloy may be treated with chromic acid before exposure to increase the degree of penetration.