Eletro-oxidative leaching of pitchblende minerals for uranium extration and determination by spectrophotometry in flow injection analysis system

• Autor(a) principal: Sousa, Alvaro Serafim Ferreira de
• Data de Publicação: 2007
• Outros Autores: Ferreira, Elizabeth de Magalhães Massena, Cassela, Ricardo, Instituto de Engenharia Nuclear, Universidade Federal Fluminense
• Tipo de documento: Artigo de conferência
• Idioma: eng
• Título da fonte: Repositório Institucional do IEN
• Texto Completo: http://carpedien.ien.gov.br:8080/handle/ien/2535
• topic: INAC 2007; Uranium extraction; Pinchblende minerals; Spectrophometry

A method for uranium extraction from pitchblende minerals samples by electro-oxidative leaching was developed. An electro-dissolution cell associated to an on line sampler system was designed and tested in order to evaluate the influence of current density, leaching time, temperature and the nature and concentration of the electrolyte on the electro-oxidative leaching process. The flow analysis system used in the uranium determination yielded analytical curves with a linear behavior (r= 0.999) in the concentration range of 0.05 to 2.0 mg L-1, a relative standard deviation of 5.5% (at 0.1 mg L-1), a detection limit of 0.02 mg L-1 and analytical throughput of 60 determination per hour. The results obtained by the developed methodology for the uranium electro-oxidative extraction from pitchblende minerals samples showed a good agreement (r= 0.999) up to 98% were achieved for one minute leaching time, with a good reproducibility. The electro-oxidative extraction system showed advantages in relation to the conventional technique, such as: possibility of automation of all analytical process, use of lower sample amounts, more swiftness in the uranium extraction and use of lower amounts of acids.