TITLE:
Silver Recovery from Spent Silver Oxide Button Cell by Liquid-Liquid Extraction
AUTHORS:
Zeferino Gamiño-Arroyo, Antonio Tapia-Cisneros, Osvaldo M. Zamacona-Saucedo, Irene Cano-Rodríguez, Alberto F. Aguilera-Alvarado, Lorena E. Sánchez-Cadena, Fernando I. Gómez-Castro
KEYWORDS:
Silver, Spent Button Cells, Leaching, Recovery
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.3 No.7,
July
16,
2015
ABSTRACT: Button cell batteries are used in clocks, thermometers,
remote controls, toys and other devices, and they are usually discarded in the trash
once its useful life is over. Some models of these batteries contain silver oxide.
In this paper we propose liquid-liquid extraction as separation process to recover
the metal. First, silver determination is performed in different models of these
batteries and leaching with nitric acid is carried out. Affinity study is done between
several commercial extractants for silver. The best performing extractant is the
bis(2-ethylhexyl) dithiophosphoric acid (D2EHDTPA). Furthermore, a study of the
extraction yields as a function of extractant concentration and time is performed.
The distribution isotherm is determined; complex extracted in organic phase and
stripping conditions have been identified. With the aim of obtaining industrial
application, a number of steps for a countercurrent process were defined by the
McCabe-Thiele method. Finally, a study was done in micropilot scale. The results
show that it is possible to recover silver from this type of waste.