US EPA

1426087 

Technical Report 

Development of DU-AGG (Depleted Uranium Aggregate) 

Lessing, PA 

1995 

NTIS/02989043_3 

GRA and I 

GRA and I 

Depleted uranium oxide (UO(sub 2) or U0(sub 3)) powder was mixed with fine mineral additives, pressed, and heated to about 1,250(degree)C. The additives were chemically constituted to result in an iron-enriched basalt (IEB). Melting and wetting of the IEB phase caused the urania powder compact to densify (sinter) via a liquid phase sintering mechanism. An inorganic lubricant was found to aid in green-forming of the body. Sintering was successful in oxidizing (air), inert (argon), or reducing (dry hydrogen containing) atmospheres. The use of ground U0(sub 3) powders (93 vol %) followed by sintering in a dry hydrogen-containing atmosphere significantly increased the density of samples (bulk density of 8.40 g/cm(sup 3) and apparent density of 9.48 g/cm(sup 3), open porosity of 11.43%). An improvement in the microstructure (reduction in open porosity) was achieved when the vol % of U0(sub 3) was decreased to 80%. The bulk density increased to 8.59 g/cm(sup 3), the apparent density decreased slightly to 8.82 g/cm(sup 3) (due to increase of low density IEB content), while the open porosity decreased to an excellent number of 2.78%. A representative sample derived from 80 vol % U0(sub 3) showed that most pores were closed pores and that, overall, the sample achieved the excellent relative density value of 94.1% of the estimated theoretical density (composite of U0(sub 2) and IEB). It is expected that ground powders of U0(sub 3) could be successfully used to mass produce lowcost aggregate using the green-forming technique of briquetting. 

Depleted Uranium; Briquetting; Experimental Data; Images; Radioactive Waste Processing; Uranium 235; Uranium Oxides; Tables(data); EDB/052001