INTERACTION BETWEEN FINELY GROUND GALENA AND PYRITE WITH POTASSIUM AMYLXANTHATE IN RELATION TO FLOTATION .2. INFLUENCE OF GRINDING MEDIA AT NATURAL PH

Diffuse reflectance Fourier transform infrared (FTIR) spectroscopy, Hallimond tube flotation cell and microelectrophoresis have been utilized to investigate the reactions involved in the adsorption-abstraction of K-amylxanthate on finely ground galena and pyrite. In order to work under well controlled conditions, pure minerals were wet ground in specially built laboratory stainless steel and iron rod mills. X-ray photoelectron spectroscopic (XPS) studies have been carried out in order to characterize the surface oxidation products after grinding. According to collector concentration, the following surface products were found to be formed on galena: monocoordinate lead xanthate, non-stoichiometric and stoichiometric lead xanthate, dixanthogen and amylcarbonate disulphide. Only dixanthogen was observed on pyrite after using stainless steel rods, while ferric iron xanthate and physically absorbed xanthate ions were found to be formed when iron rods were utilized. The use of iron grinding media slightly depresses the floatability of galena and pyrite.