| The purpose of this investigation was to evaluate the flotation of five copper minerals (chalcopyrite, chalcocite, bornite, covellite, malachite) and pyrite using rate and recovery data. Over 80 collectors, representing sulfhydryl, colloidal electrolyte and chelate-forming types at three pH values (5.0, 8.5 and 10.5), were studied to determine the effect of R-chain length and branching, number of R-chains in a collector, heteroatoms present in the collector and relative positions of these heteroatoms to each other and their respective R-chains.; Mechanisms were proposed for specific mineral-collector systems based on both a previous study (Ackerman, P. K., "Evaluation of Flotation Collectors for Copper Sulfides and Pyrite Using Rate and Recovery Criteria", M.S. Thesis, The Pennsylvania State University (1983)) and the current studies. The characterization of the minerals included their electrokinetic behavior, semiconductor type and solubility, while the characterization of reagents involved their solubility, ionization, decomposition and oxidation. The flotation response of the various mineral collector systems have been grouped into five categories: (1) Floats sulfides well pH 5-10.5. (2) Floats sulfides well, but not pyrite pH 5-10.5. (3) Floats sulfides well, but not pyrite pH 5.0. (4) Mediocre flotation of sulfides. (5) Poor flotation of sulfides.; The study showed convincingly that a specific collector type can be optimized by manipulating the R-chain length of the substituents, the branching of the substituents or the point of attachment of the substituents to the collector.; A separate study of the effect of changing the heteroatom(s) or its (their) position in a collector was also made. Varying the heteroatom in a collector from nitrogen to sulfur to oxygen generally increases the strength of collection but decreases the selectivity of the collector against pyrite. If a heteroatom(s) has an alkyl substituent attached to it, the length and branching of that substituent affects the strength of attachment of the collector to the mineral.; Consideration of the data shows that to some extent, a collector can be designed for a specific purpose based upon a knowledge of the separation desired and the characteristics of the collector (substituent length, heteroatoms present and specific combinations and positioning of those heteroatoms). |
