Report on chemical impurities in lots of 2020 graphite

Chemical and physical studies on agglomerated and dispersed impurities found in three lots of 2020 graphite received from the Stackpole Company are described. Each lot consisted of three billets, one shipment of off-the-shelf 2020 and two of ``nuclear quality`` graphite for which efforts had been taken to decrease impurity levels. An earlier report described the results of chemical analyses of the three lots of graphite and the gross distribution of the impurities in the billets. The present report describes the chemical and physical studies on the detailed distribution and chemical identity of the agglomerates that led to the identification of their source. Agglomerated impurities were found in all lots of 2020. The particles possessed an average size range of about 0.3 mm. In addition to these particulates, other inorganic ash forming components were found to be rather more uniformly distributed internally throughout the graphite. 4 refs., 4 figs., 3 tabs