Development of mineralogy-based approaches to study the loss of copper minerals into tailings of scavenger flotation circuit – Part I

Loss of copper minerals to tailings of the rougher and scavenger circuits is one of the challenges in copper concentration plants, which reduces the efficiency of the circuit. The goal of this research is to utilize mineralogy-based techniques to identify the cause of the loss of copper minerals to tailings of the scavenger circuit. Process mineralogy studies have been performed on the scavenger of the flotation circuit - the Sungun copper concentration plant (located in northwestern of Iran). First, the feed, final concentrate, and tailing, as well as the concentrate and tailing flows of each of the scavenger circuit cells were sampled at different time intervals. Then, chemical composition analysis, laser particle size distribution analysis, and optical microscopy studies were performed on them. According to the results, the presence and changes in the abundance of copper oxide minerals, which make up about 45% of copper minerals, is one of the main reasons for the copper loss to tailings. Also, fine-grained particles of copper sulfide minerals (d80~45 µm), and the interlocking of copper sulfide minerals, especially chalcopyrite, with pyrite and gangue minerals (silicate), are among the most important causes of increased copper grade in the scavenger circuit tailings. In addition, the malfunction of the scavenger circuit cells due to the simultaneous presence of sulfide and oxide minerals and their fineness is another cause of the lost to tailings.