Uranium recoveries in excess of 99% were achieved using ion exchange technology on uranium-loaded acid solutions from the leaching of Macusani uranium ores.
After positive leaching of the uranium in leaching columns, the loaded acid solutions were transported to Cwenga Laboratories in Johannesburg, South Africa, for ion exchange metallurgical testing.
The metallurgical tests have been able to successfully extract uranium from the leaching solutions obtained from Macusani, Puno, Peru.
The initial test work suggested that various ion exchange resins were able to load uranium from these solutions and after a selection process, two grades were chosen for column loading tests.
The uranium was loaded onto the selective ion exchange resin using two columns in series.
At the first pass, a recovery of 80% was obtained and after the final column, 98% of the remaining uranium was removed, for a grand total of 99.6% recovery.
Essentially, all the dissolved uranium can be removed by this selected ion exchange process.
The uranium was eluted from the resin using a weak acid environment while the excess sulphate was removed by liming and precipitation of gypsum, which was filtered off.
The resultant filtered solution was reacted with various reactants in order to produce a precipitate of uranium oxide.
After filtering and drying, a product was obtained, commercially known as ‘Yellow Cake’.
At this stage, the metallurgical ion exchange concentration and elution are well understood and the process of optimization continues.
