UBC Theses and Dissertations
Studies on the flotation depression of chalcopyrite, galena and sphalerite by thioglycollic acid Liu, Qi
Thioglycollic acid (TGA) was found to exhibit strong depressive action on chalcopyrite, galena and sphalerite samples. This depressive action resembled hydrosulphide in that the contact curve of TGA was very similar to that of sodium sulphide. An adsorption model was proposed based on the experimental observations. The model suggests that TGA molecules adsorb onto sulphide mineral surfaces through either their mercapto groups, or their carboxyl groups, with subsequent multilayer adsorption of TGA onto this chemisorbed layer through hydrogen bonding and oxidative dimer bonding. The TGA molecules adsorbed through the carboxyl group were not responsible for the observed depression: these molecules were easily desorbed by potassium ethyl xanthate. Oxygen was found to enhance the adsorption of TGA onto sulphide mineral surfaces and consequently, to enhance the depressive action. The selective separation of synthetic sulphide mineral mixtures with the use of TGA has met limited success.