Abstracts Book - IMRC 2018

• SB1-P046
PREPARATION AND CHARACTERIZATION BY SEM OF A
POLYMERIC MEMBRANE USED IN PRECIOUS METALS
SEPARATION
María Elena Núñez Gaytán 1 , Ana María Núñez Gaytán 1
1 Universidad Michoacana de San Nicolás de Hidalgo, Facultad de Ingeniería Química, Mexico.
Liquid-liquid extraction has been used for the separation and concentration of
precious metals and platinum group metals. However, some limitations of this
technique (i.e. need of large volumes of the different phases, loss of high cost
extractants and solvents, and use of potential hazardous solvents), as well as
economical aspects have limited the scaling up of successful laboratory
operations. At the same time, the use of polymeric membranes has increased
during the last years as an alternative to liquid-liquid extraction mainly because
it allows the diminishment of some reagents consumption (solvents and
extractants) and the possibility of facilitating the automatization of the process
since the extraction and stripping operations can take place in one step
operation [1,2]. In this work, studies based on polymeric inclusion membranes
(PIMs) operations for gold recovery concentrated hydrochloric acid media have
been performed with selective extractans/carriers. Studies were performed
using an organic phosphate compound as carrier. Polymeric inclusion
membranes were synthesized using cellulose triacetate as polymeric support
and tris(2-ethylhexyl) phosphate as plasticizer and carrier or extractant. 25
membranes were tested for the transport of Au(III), Cu(II) and Pd(II) by operation
cycles of 180 min a constant temperature. A polymeric membrane composition
with 50% of carrier/plasticizer showed the best separation of gold. The
membrane don’t transport Cu(II) and Pd(II). So, it was selective for gold
separation Cu(II) and Pd(II). The best polymeric membrane showed an efficient
extraction of gold using a solution containing 0.2 mM Au(III) in 1 M concentrated
hydrochloric acid media as the feed phase and 0.1 M NaCl as the receiving
phase. An 87% of gold was stripped. The membrane was characterized using
scanning electron microscopy (JEOL JSM-IT500).
References
[1] P. R. Danesi; “Separation of metals species by supported liquid membranes”;
Separation Science and Technology, Vol. 19, No. 11, (1984).
[2] L. D. Nghiem, R. W. Cattrall, Extraction and transport of metal ions and small