The wettability of electrodes made of natural metal sulfides

Experimental methods for the evaluation of the wettability of electrodes made from natural mineral sulfides are discussed for the case of potentiostatic polarization. The wettability, induced by xanthates with different lengths of the alkyl chain, was studied for the case of pyrite, chalcopyrite, galena, arsenopyrite and chalcocite. Therefore measurements of the detachment force of an air bubble (ABDF) and of the induction time (ABIT) were performed. The first of these allows us to estimate the conditions for the destruction of the bubble-mineral complex, and the second allows us to estimate the conditions of aggregate formation under collision. The study was carried out at various polarization potentials in a borate buffer solution. The results of the measurements are compared with thermodynamic data and with experimental results obtained for representative cases such as xanthate sorption and flotation recovery. A correlation of the flotation experiments with the ABDF results can be demonstrated. Received: 28 February 1997 / Accepted: 12 August 1997