Potential uranium supply from phosphoric acid: A U.S. analysis comparing solvent extraction and Ion exchange recovery

Abstract

Phosphate rock contains significant amounts of uranium, although in low concentrations. Recovery of uranium as a by-product from phosphoric acid, an intermediate product produced during the recovery of phosphorus from phosphate rock, is not unprecedented. Phosphoric acid plants ceased to produce uranium as a by-product in the early 1990s with the fall of uranium prices. In the last decade, this topic has regained attention due to higher uranium prices and expected increase in demand for uranium. This study revisits the topic and estimates how much uranium might be recoverable from current phosphoric acid production in the United States and what the associated costs might be considering two different recovery processes: solvent extraction and ion exchange.Based on U.S. phosphoric acid production in 2014, 5.5 million pounds of U3O8 could have been recovered, which is more than domestic U.S. mine production in the same year (4.9 million pounds U3O8). In comparison, uranium demand from U.S. nuclear plants in the same year was 53 million pounds U3O8 of which nearly 10% could have been met by uranium from phosphoric acid production. Annualized costs for a hypothetical uranium recovery plant are US$44–61 per pound U3O8 for solvent extraction, the process used historically in the United States to recover uranium from phosphoric acid. For ion exchange, not yet proven at a commercial scale for uranium recovery, the estimated costs are US$33–54 per pound U3O8. These results suggest that it is technically possible for the United States to recover significant quantities of uranium from current phosphoric acid production. For this type of uranium production to be economically attractive on a large scale, either recovery costs must fall or uranium prices rise.