Abstract: Various methods have been proposed to separate precious metal from a fluid utilized for plating. The known methods and devices are complicated and expensive. To overcome this problem, a method and a device for plating work pieces with a fluid containing at least one precious metal are provided. According to the invention the work pieces are contacted with the fluid and the fluid is filtered, after use, through at least one ceramic membrane filter in order to separate the at least one precious metal from the fluid. According to the invention a ceramic membrane filter having an exclusion pore size in excess of 10,000 Dalton is utilized.
Abstract: There is provided a high-purity ruthenium sputtering target with a low impurity content, in particular producing extremely few particles, which is suitable for applications such as the formation of semiconductor thin films. The high-purity ruthenium sputtering target is manufactured by feeding crude ruthenium powder into a sodium hydroxide solution; blowing an ozone-containing gas while or after blowing chlorine gas into the solution to form ruthenium tetroxide; absorbing the ruthenium tetroxide in a hydrochloric acid solution or a mixed solution of hydrochloric acid and ammonium chloride, and evaporating the solution to dryness; sintering the resultant ruthenium salt in a hydrogen atmosphere to form high-purity ruthenium powder; and hot-pressing the ruthenium powder into a sputtering target.
Abstract: This invention is a method for the recovery of precious metal selected from the group consisting of platinum and rhodium lost from a platinum-containing catalyst during ammonia oxidation processes at a temperature above 850.degree. C. which comprises bringing said lost precious metal into contact with a foraminate element fabricated from a material consisting essentially of palladium, by itself, or palladium and a minor amount of another metal selected from the group consisting of other platinum group metals, Ni, Au, Mn, Mg, Cr, C, B, Cu and alloys of mixtures thereof characterized by (a) a novel configuration whereby the initial product of the formula: curve to flat ratio (C/F) multiplied by mesh size (N) and wire diameter (d.sub.w), for the element is greater than at least about 0.9 and (b) where, for a given nitrogen throughput, the weight recovery efficiency is a function of the curve to flat ratio (C/F), wire diameter (d.sub.
Type:
Grant
Filed:
June 17, 1991
Date of Patent:
June 16, 1992
Assignee:
Johnson Matthey Inc.
Inventors:
William A. Hochella, Steven A. Heffernen