A countercurrent, multistage ion-exchange column, initially developed for recovering uranium from dilute mine waters, also proved effective for handling clear solutions and slime pulps prepared by leaching uranium ores. In pilot plant tests, clear solutions and slime pulps containing up to 8 percent solids were processed at the exceptionally high flow rate of 15 gallons per square foot per minute, with high recovery and efficient loading of resin. A single-stage ion-exchange column was developed for eluting uranium from resins under countercurrent flow conditions. Substantially complete elution can be achieved using only 2 to 4 volumes of solution per volume of resin. Because of simple design, low construction cost, high throughput rates, low maintenance, ease of automation, and reduced resin requirements, use of these new types of ion exchangers enables substantial reductions in the cost of processing uranium ores. A cost estimate for a uranium-ore processing mill, using these new types of ion-exchange columns in a resin-in-pulp system, shows that capital costs for such a plant would be about 27 percent lower than for a mill employing thickeners and solvent extraction or conventional ion exchange. In addition a significant reduction in direct operating cost can be expected for the simpler and more readily automated plant.
Proc. Symp. Recovery of Uranium, Aug. 17-21, 1970, Sao Paulo, Brazil, 1971, PP. 297-309