Selective thorium and uranium extraction from monazite: I. Single-stage oxalate leaching

Add time:09/24/2019    Source:sciencedirect.com

The selective leaching of thorium and uranium from monazite with ammonium oxalate was studied at near ambient temperatures, as a function of pH, particle size, phosphate and oxalate concentration, and temperature. The thermodynamic speciation showed that the presence of phosphate seriously restricted the solubility of both metals, while the solubility of thorium was also lowered by the formation of solid thorium oxalate in the moderately to strongly acidic pH region (pH < 3). Experimental evidence indicated that once the optimum pH was determined, the extent and velocity of both thorium and uranium extractions were modestly affected by the temperature, but greatly by the particle size. Regardless of conditions, complete recovery of thorium and uranium could not be achieved, apparently because of passivation of unreacted monazite cores by recrystallized rare earth phosphates or precipitated oxalates.

We also recommend Trading Suppliers and Manufacturers of CERIUM(III) OXALATE (cas 15750-47-7). Pls Click Website Link as below: cas 15750-47-7 suppliers

Prev:Cerium oxide for the destruction of chemical warfare agents: A comparison of synthetic routes
Next:ReviewRecycling and substitution of light rare earth elements, cerium, lanthanum, neodymium, and praseodymium from end-of-life applications - A review)