The extraction and purification of uranium from columbite-tantalite

In this study of the extraction and purification of Uranium from Columbite - Tantalite, the ore was taken from Uthai Thanee province of Thailand. This ore was rather difficult to leach because it contained large amount of Tantalum, Niobium and Tin. The experiment was performed to find conditions to leach the ore by using sulphuric acid. Effect of parameters such as acid concentration, oxidants, time, temperature and particle sizes on the degree of Uranium leaching were investigated. About 37.8% of a leaching yield was obtained from the sample size - 200 mesh (50%), 12.5 w/v of sulphuric acid, 1.6% of oxidant (Mn O2), 17% w/v of ore sample and 7 hours leaching time at 80 ±1 degree C. Two steps of purifying the uranium solution were attempted, firstly by ion exchange method using Amberlite IR A 400 (SO4=) resin and then eluate uranium with 1.0 M. sulphuric acid. Secondly, by amine solvent extraction and then precipitation by sodium hydroxide solution. The yellow cake product was found to contain uranium about 67%