ACTIVITION MECHANISM OF CU(II) AND NI(II) IONS TO THE FLOTATION OF
SERPENTINE
ABSTRACT
Serpentine is the main magnesium silicate gangue mineral in JINCHUAN copper-nickel sulfide ore. It
is difficult to decrease MgO content in the copper and nickel flotation concentrate because serpentine
can be activated by Cu2+, Ni2+ ions in flotation pulp. However, the activation mechanism of Cu2+,
Ni2+ ions on serpentine is still unknown. In this paper, the adsorption and activation mechanisms of
Cu2+ and Ni2+ ions on serpentine have been investigated through adsorption measurements, pure
mineral flotation tests and IR spectra analyses. The results show that the adsorption of Cu2+, Ni2+ ions
on serpentine agrees with the second order kinetics model, the isothermal adsorption process
correlates well with the Langmuir isotherm model. The adsorption is a spontaneous process, which is
caused jointly by physical and chemical functions. The adsorption amount of Cu2+ and Ni2+ ions on
serpentine increases with the increase of pH. Under weak alkaline condition, serpentine can be
activated by Cu2+ and Ni2+ ions. The active sites can be formed on the surface of serpentine after
reacted with hydroxide and hydroxy complexes of copper and nickel, on which xanthate can be
adsorbed to generate copper and nickel xanthates. These hydrophobic products increase the surface
hydrophobicity of serpentine and thus activate its flotation.
Figure 1 –Activation process of Cu2+, Ni2+ ions to serpentine (Me represents Cu, Ni; X represents xanthate)
KEYWORDS
Serpentine, Copper ions, Nickel ions, Adsorption, Activation mechanism