Silver Recovery from Spent Silver Oxide Button Cell by Liquid-Liquid Extraction

Zeferino Gamiño-Arroyo,Lorena E Sánchez-Cadena,Fernando I Gómez-Castro,Irene Cano-Rodríguez,Alberto F Aguilera-Alvarado,Antonio Tapia-Cisneros,Osvaldo M Zamacona-Saucedo

doi:10.4236/msce.2015.37020

Zeferino Gamiño-Arroyo, Lorena E Sánchez-Cadena + Show 5 more

Open Access

https://doi.org/10.4236/msce.2015.37020

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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.

Highlights

The batteries and cells are storing devices of electrochemical energy which as released like electricity when supplies an external circuit
Depending on how long the charge lasts the cells are classified in primary and secondary, the primary are based on an irreversible chemical reaction, cannot be recharged and have only one life cycle
The used batteries can be seen like side product of many electronic and portable devices

Summary

Introduction

The batteries and cells are storing devices of electrochemical energy which as released like electricity when supplies an external circuit. Depending on how long the charge lasts the cells are classified in primary and secondary, the primary are based on an irreversible chemical reaction, cannot be recharged and have only one life cycle. The secondary cells perform a reversible chemical reaction, can be recharged, and their active components are regenerated supplying electrical current in the opposite way to discharge. The used batteries can be seen like side product of many electronic and portable devices. The batteries can be classified according to the technology they use, their presentation and applications.

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