TITLE:
Solvent Extraction of Nickel and Cobalt from Ammonia-Ammonium Carbonate Solution by Using LIX 84-ICNS
AUTHORS:
Mohammad Zaki Mubarok, Fariza Eka Yunita
KEYWORDS:
Nickel, Cobalt, Ammonia-Ammonium Carbonate, Solvent Extraction, LIX 84-ICNS
JOURNAL NAME:
International Journal of Nonferrous Metallurgy,
Vol.4 No.3,
June
18,
2015
ABSTRACT: In the present paper, separation of nickel and cobalt in ammonia-ammonium carbonate solution
that simulates pregnant leach solution of Caron Process by solvent extraction using LIX 84-ICNS
was studied. LIX 84-ICNS is a novel extractant which is still being studied, especially for nickel and
cobalt separation in ammonia-ammonium carbonate solution. A series of solvent extraction tests
were performed at various equilibrium pH, temperature, extractant concentration, and volume
ratio of organic to aqueous solution (O/A ratio). The investigation results show that the highest
nickel and cobalt extraction percentages of 99.8% and 90.3% were obtained from the extraction
test at equilibrium pH of 8.75, temperature of 55°C, extractant concentration of 40% (v/v) and O/A
ratio of 1/1, respectively. Oxidation of cobalt in aqueous solution prior to extraction is needed to
minimize co-extraction of cobalt. Co-extracted cobalt can be decreased from 90.3% to 30.3% by
mixing 1% (v/v) H2O22 in aqueous solution prior to the extraction stage. It was found that nickel
and cobalt extractions by LIX 84-ICNS are endothermic processes with enthalpy changes of
+171.03 and +7.64 kJ/mole, respectively. Based on constructed McCabe-Thiele Diagram, nickel
extraction level of more than 99.9% can be obtained in 2 stages at O/A ratio of 0.5. The highest
stripping percentages of nickel and cobalt of 98.82% and 3.16% respectively were obtained at 200
g/l H2SO4 stripping agent.