The Caldag nickel laterite project is located inland of Izmir, in Western Turkey. Ownership of the project passed from ENK PLC (previously European Nickel) to Caldag Nikel, a subsidiary of VTG Holdings, in 2011. Caldag ores have historically exhibited excellent response to leaching at atmospheric pressure. The mineralogical features contributing to this behaviour have been considered. The original heap leaching concept has been abandoned in favour of agitated atmospheric tank leaching due to higher product revenue and restrictions placed on site development activities. Extensive testwork has been conducted to support the development of an agitated atmospheric tank leach process to treat the Caldag ores. Means of dealing with the pitfalls of atmospheric leaching for nickel laterites have been examined. Ore preparation, leaching and iron removal testwork has been completed, supported by extensive process modelling undertaken in pursuit of an optimised process flowsheet. Several process flowsheet options have been assessed using METSIM~R process simulation software. The key issues for process development have been (a) minimising sulphuric acid consumption and (b) controlling iron sulphate concentration in leach liquors to prevent basic ferric sulphate formation.
展开▼
