The Determination of Free (Uncombined) Carbon in Plutonium Carbides

摘要

Free (uncombined) carbon in plutonium carbide is determined gravimet-rically following dissolution of the sample in hydrochloric acid and ignition of the free carbon to carbon dioxide at 1000° C in oxygen. The plutonium carbide is placed on an asbestos mat held by a perforated porcelain disc near the bottom of a 55-mm. length of fused silica tubing and dissolved in hydrochloric acid. The tars formed by this dissolution are washed from the mat with acetone. The filter tube is dried under heat lamps and placed in a tube furnace for the oxidation of the carbon to carbon dioxide which is absorbed in an Ascarite-filled tube and weighed. Relative standard deviations for determinations of free carbon in four plutonium carbide samples were in the range of 6 to 11%. These percentages include differences in results caused by possible heterogene¬ity of the samples in addition to deviations inherent in the method of measurement. It was concluded that the relative standard deviation of the method was no greater than 10%.