RECOVERY OF INDIUM FROM ZINCE OXIDE FLUE DUST
Honglin Luo1, Wei Liu2, Wenqing Qin2
1 Changsha Non-ferrous Metallurgy Designe&Research Institute Company Limited
2 Central South University
Abstract: The main purpose of this study was to extract indium from the zinc oxide flue dust
(ZOFD), which contained 753 g/t indium. Two-stage leaching process to recover indium from the
ZOFD was investigated. The conditions for neutral leaching were optimized at 60 °C for a duration
of 30 min with 0.16 M sulfuric acid and a liquid/solid ratio of 10 mL/g. In the neutral leaching, zinc (>
95%) was selectively leached into the solution and indium (> 95%) was concentrated in the residue,
which indicated the successful selective separation of zinc and indium. The dissolution rate of
indium was more than 88%, under 80 °C, 0.8 M sulfuric acid, liquid/solid ratio 6 mL/g
reaction
time
of
2
di(2-ethylhexly)-phosphoric
h.
The
conditions
in
extraction
of
indium
and
by
acid (D2EHPA) were optimized that organic phase: 30% D2EHPA
and 70% kerosene, aqueous phase/oil phase ratio (A/O): 4 and initial acid concentration of the
aqueous solution: 1-1.5 M, the fraction extracted of indium from solution was more than 95%.
Keywords: Indium, zinc oxide flue dust, leaching, solvent extraction