PRECIOUS METALS

Author: RIVERA LANDERO ISAURO.
Year: 2003.
University: BARCELONA [www.ub.es].
Place of defense: QUÍMICA.
Place of preparation: FACULTAD DE QUÍMICA.

Summary: Recovery of silver complejada with thiosulphates and in industrial effluent is attractive for its high value económico.Estos effluents are classified as toxic waste and can not be assessed to public channels without pretreatment of detoxification. One of the proposed methods to recover silver from the effluent is precipitation chemistry used ditionito of sodio.En This paper discusses the most significant aspects of the use of this reagent for obtaining metal ditionito sodium, effluent thiosulphates basis, sineliminación other species, you put manifest capacity ditionito to meet the objectives of achieving an almost total precipitation of the silver (recoveries greater than 99.9%), leaving the metal in the effluent treated at lower levels than 1ppm, without introducing foreign substances to sistema.Se first presents the estequiometría the reaction of precipitation and performed an exhaustive study of the kinetics of the reaction itself, submitted units of the variables involved such as speed agitation system agitation, temperature, OH concentration, concentration S2O32- concentration S2O42-, concentration of silver, nucleación.Además, an optimal recovery process effluent with silver metal recoveries close to 100% and getting the only kind precipitate metallic silver high purity. Moreover, it presents a study on the leaching of silver in a novel and potentially attractive, the leaching of metal system O2-S2O32-, presents the estequiometría the leaching reaction and is the kinetic study of the reaction presented units of the variables involved such as: agitation speed, temperature, pressure O2 concentration S2O3 2-, concentration of H3O +, the presence of catalizadores.Finalmente, suggests optimal conditions for leaching of matel, which were applied to dust silver, with recoveries of 42% in 240 min.