Recovery of locked-up uranium in slag disc by co-melting in magnesio-thermic reduction

Synthetic diversity in the preparation of metallic uranium

“…This firing with a sudden rise in temperature from the exothermic reaction [ 35 , 41 ] is observed using a temperature recorder. Owing to its high density, uranium metal settles at the bottom of the crucible allowing its separation from the slag and other reaction products, primarily MgF 2 ; the quality of this separation is an important factor for yield [ 40 ]. A typical UF 4 /Mg load in a graphite crucible is shown in figure 2 [ 8 ].…”

“…A typical UF 4 /Mg load in a graphite crucible is shown in figure 2 [ 8 ]. Yields of approximately 80–96% have been reported depending on uranium recovery methods [ 8 , 40 ]. The most significant parameters on controlling firing time include the tap density of UF 4 , the moisture, the free acid content in UF 4 , the Mg particle size and the oxide presence in Mg [ 35 ].…”

“…The former poses complications owing to NO x production and fluoride contamination, and the latter requires an additional cost-intensive set-up. The co-melting of slag discs was investigated as a third method and did not require additional set-up [ 40 ].…”

“…UF 4 /Mg) uses the heat generated from the exothermic reaction. Thirty batches were co-melted using one slag disc each [ 40 ]. The slag discs (4–16 kg) were able to co-melt with the charges (approx.…”

“…This method was shown to be simple and cost-effective and presents high potential for the uranium recovery from old stock. However, impurities from slag discs can build up in the metal product, and the amount of slag per batch is limited by thermodynamic constraints [ 40 ].…”