Uranium in sulfuric acid medium is selectively extracted by tertiary amine. Uranium stripping from the loaded solvent (tertiary amine) can be carried out by many salt and acid solutions. The stripping agent choice depends on several factors, such as organic composition and economic viability. In the present work, the uranium stripping by (NH4)(2)SO4 was investigated in order to substitute the NaCl used in the production of uranium concentrate by "Industrias Nucleares do Brasil (INB)". The (NH4)(2)SO4 concentration, the equilibrium pH effect and the presence of chloride ion in the loaded organic phase were investigated. It was observed that the presence of chloride ion in the loaded organic phase makes the (NH4)(2)SO4 stripping process unfeasible. In this case, only 65% of the uranium was stripped. In the absence of chloride, it was possible to obtain a pregnant strip solution with 33 g/L U3O8 and an unloaded organic solution with 0.006 g/L U3O8 using five mixer-settler stages. (c) 2005 Elsevier Ltd. All rights reserved.