Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr
Issue link: https://emj.epubxp.com/i/148853
F LO TAT I O N Figure 3—As shown in this graph, EFD's HydroFloat was able to recover more than 95% of gold values contained in a feed stream from a conventional gravity separation circuit, at a concentration ratio of more than 100:1 and all in a single stage. has been shown that a large source of particle-bubble disengagement or "froth drop-back" occurs at the froth-pulp interface due to buoyancy issues. HydroFloat has numerous installations in industrial minerals applications, and EFD is currently targeting two additional applications. The first is basemetal sulphide applications. Currently, the most expensive part of any mineral processing flowsheet in terms of capital and operating cost is the grinding circuit. This is because conventional flotation cannot efficiently recover ore particles beyond about 250 microns, and hence this limitation drives the requirement to produce a fine grind size from the primary mill. By using the Hydro- Float, which can efficiently collect coarse particles, the grind size can be increased without sacrificing metal recovery. As a result, the mill throughput can be increased and the grinding costs per ton of ore can be decreased. This innovation is proving to be a very important part of the value proposition in regions with high power costs. Another application is in the area of coarse gold recovery. EFD has completed test work (lab work followed by an on-site pilot campaign) to investigate the floatability of coarse alluvial gold from a dredging application in Central America. In this application, a single stage of the HydroFloat was installed to treat the low-density stream from a conventional gravity separation unit. The results are shown in Figure 3. Starting from a feed grade of 3–4 g gold per metric ton, the HydroFloat was able to recover more than 95% of the gold values at a concentration ratio of more than 100:1, all in a single stage. These examples show how the Eriez Flotation Division continues to develop new technology to improve and innovate within the minerals processing field. The key ingredients are a global staff of flotation experts and customers who are willing to share their problems and partner in the demonstration and commercialization of new technology to solve those problems. Dr. Wasmund is global managing director for the Eriez Flotation Division, based in Vancouver, Canada. Stage-Gate® is a registered trademark of the Product Development Institute. Tank Feed Air Jet installation at a base metal plant in South America. 46 E&MJ; • AUGUST 2013 www.e-mj.com