A1 Journal article (refereed), original research

Membrane Filtration Enhanced Hydrometallurgical Recovery Process of Indium from Waste LCD Panels


Open Access hybrid publication

Publication Details
Authors: Lahti Jussi, Vazquez Sergio, Virolainen Sami, Mänttäri Mika, Kallioinen Mari
Publication year: 2020
Language: English
Related Journal or Series Information: Journal of Sustainable Metallurgy
ISSN: 2199-3823
eISSN: 2199-3831
JUFO-Level of this publication: 1
Open Access: Open Access hybrid publication
Location of the parallel saved publication: http://urn.fi/URN:NBN:fi-fe2020100678152

Abstract

Insufficient recycling of a continuously increasing amount of liquid
crystal display (LCD) waste leads to the waste of potentially recyclable
materials, especially rare and critical indium. Moreover, landfilling
of LCD waste increases the potential for environmental risk. This paper
describes a recycling process combining membrane filtration unit
processes to hydrometallurgical indium recovery process. The LCD panels
were crushed and leached with 1 M H2SO4. 97.4%
yields on average were obtained, and a novel finding was made about fast
kinetics (2 min for the maximum indium yield). Ultrafiltration was used
to remove the dissolved organic material from the leachate, which was
concentrated with nanofiltration before liquid–liquid extraction for
indium purification. The results showed that commercial polymeric
membranes removed more than 90% (from over 3000 mg/L to under 200 mg/L)
of the dissolved organic compounds, thus potentially significantly
diminishing the detriments caused by these compounds in the
liquid–liquid extraction step. The concentration of the leachate with
nanofiltration enables the use of smaller processing equipment and to
save chemicals in the further steps of the process. The indium content
in the leachate was more than five times higher after nanofiltration
than after leaching (126 mg/L vs. 677 mg/L). In liquid–liquid
extraction, the phase separation took place in only 34 s with the
membrane-treated leachate, while with the untreated leachate it remained
incomplete even after three hours. The purity of indium was increased
from 10 to 74%. From the obtained HCl solution, a 95.5% pure indium
product with 69.3% yield was obtained by cementation.


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Last updated on 2020-04-11 at 12:10