Adsorption mechanism of diethyldithio carbamate on covellite, cuprite and tenorite

Abstract

Adsorption of diethyldithiocarbamate (DTC) on covellite, cuprite and tenorite was investigated under different experimental conditions. The qualitative nature of surface species formed at the interface was examined by selective solvent extraction and UVvisible spectrophotometric techniques. The presence of surface species such ::lB [Cu(DTC)]+, Cu(DTC)2and Cu(I) DTC at different concentrations of the reagent and pH of the suspension was investigated. The results of this study indicate a surface reactionbetween DTC ligand molecules and surface copper sites. As a result of interaction with DTC, cations on the mineral surface are dislodged from the lattice and precipitated on the surface as copper dithiocarbamate complexes. Depending on the concentration of DTC, two types of copper complexes, i.e. [Cu(DTC)]+at low concentration and Cu(DTCh at higher concentration, are noted on copper(II) substrates, whereas on cuprite Cu(I) DTC was formed along with [Cu(DTC)]+ and Cu(DTCh. From the kinetic study, the overall adsorption was found to be mainly controlled by diffusion processes.