Studies on the interaction of guar gum with chalcopyrite

Adsorption, electrokinetic and flotation studies have been carried out to investigate the interaction of guar gum with chalcopyrite. The adsorption density of guar gum onto chalcopyrite shows a weak adsorption maximum at pH 9.5. The adsorption isotherms exhibit Langmuirian behaviour. The electrophoretic mobilities of chalcopyrite are decreased in proportion to the added concentration of guar gum. Flotation tests reveal that guar gum depresses chalcopyrite in agreement with the adsorption data. Dissolution experiments indicate release of lattice metal ions from chalcopyrite, while co-precipitation and conductivity tests confirm guar gum-metal ion interaction in the bulk solution. The pH of maximum co-precipitation between guar gum and copper species is observed in the range 9-9.5. The adsorption process is governed primarily by chemical interaction between the hydroxyl groups of guar gum and hydroxylated chalcopyrite apart from hydrogen bonding. Fourier Transform Infrared Spectrometer (FTIR) and X-ray Photoelectron Spectroscopic Studies (XPS) provide evidence in support of the interaction mechanisms proposed.