| 摘要 |
1,125,108. Vitreous glazes. ENGELHARD MINERALS & CHEMICAL CORP. 21 June, 1966 [22 June, 1965], No. 27766/66. Heading C1M. [Also in Divisions B1 and C7] Diffusion elements for hydrogen separation comprise porous ceramic bodies coated with a vitreous glaze, generally 1Á-1 mil. thick, containing 50-95% by wt. of a finely divided hydrogen-permeable metal embedded therein. The hydrogen-permeable metal may be Pd or Pd alloys containing by wt. 5-40% Ag, or 10-40% Au. They may be made by direct application of a mixture of finely divided glaze with finely divided metal in the required proportions to the support and then firing to the fusion temperature of the glaze, or by applying a suspension of glaze in a solution of an organic film forming compound to the support and firing, the suspension being such that glaze and metal are deposited in the correct proportions. Multiple coatings may be used, each being fired before the next application. Other specified alloying metals include Ni, Pt and Ru. Preferred glazes melt at temperatures higher than the normal operating temperatures of hydrogen diffusion units (400-800‹ C.) and below the softening temperature of the ceramic support, so that the support does not suffer distortion and loss of porosity during the firing of the glaze. Suitable glazes fusing at about 1000‹ C. have compositions which comprise the oxides of Al, Si, B, K,. Na, Ca, Sr and Ba. Oxides; e.g. those of Pb and Bi, which are likely to be reduced to the metal at the operating. temperature should not be included. Suitable ceramic supports comprise by wt. 50-90% Al silicates, 10-50% clay and 0-10% silica. |
