| 摘要 |
<p>A foraminate element for recovery of platinum and/or palladium and/or rhodium lost from a platinum and/or palladium and/or rhodium-containing catalyst comprising a substrate containing palladium or a palladium alloy thereon in a thickness of about 0.005 to about 0.03 cm. The palladium or palladium alloy may be coated, plated or clad onto the substrate or is preferably deposited on a surface of the substrate by a thermal spray process, thick film application or a sputter coating process. The substrate may be a solid structure possibly made from graphite, glass, silicon, a ceramic, a metal or a metal alloy and a composite of a metal and non-metal having a plurality of openings therein or a fiber or wire screen.If the substrate is a screen, it preferably has a mesh size of less than 1 to about 320 fibers or wires/cm and an area of at least about 900 cm2. Preferably, the substrate comprises a base metal which is stable at temperatures as high as 1200 °C and may be a metal or alloy such as an aluminum-chromium-iron alloy, a stainless steel alloy, a nickel-chromium alloy, a nickel-chromium-iron alloy, a nickel-chromium-iron-aluminum alloy, a nickel-base superalloy, an iron-base superalloy or a cobalt-base high temperature alloy. The foraminate element is especially useful for recovering platinum and/or palladium and/or rhodium lost during the course of an ammonia oxidation process.</p> |
