12 - Flotation of Copper Sulfide Ores

Abstract

Flotation properties of individual copper minerals and associated sulfides from natural ores differ significantly. The mineralogy of the ore mineral impurities in a crystal structure, variation in crystal structure, other interfering gangue minerals, and the liberation characteristics of individual minerals in a particular ore are some of the factors that influence flotation properties of an individual mineral. The most influential factor is the preferential grinding of different copper minerals according to their hardness. In a large number of the older operating plants that use conventional rod mill/ball mill grinding, there is a tendency to convert the conventional grinding circuits into a SAG mill/ball mill grinding configuration. All the new plants are currently using the SAG mill/ball mill circuit. Reagent schemes used for the treatment of porphyry copper and copper–molybdenum ores are relatively simple and usually involve lime as a modifier, xanthate as the primary collector and a secondary collector. The secondary collector type varies from operation to operation and is selected from a variety of collectors including dithiophosphates, mercaptans, thionocarbamates, xanthogen formates, etc. The floatability of molybdenum during copper flotation depends on many factors, including type of collector, type of frother, flotation pH, and type of hydrocarbon oil used.