NICKEL LATERITE PROCESSING: SECOND GENERATION DESIGN CONSIDERATIONS

摘要

In the past decade Australia has seen therndevelopment, construction and commissioning ofrnthree complex processing plants for the treatment ofrnlateritic nickel ores. These have all been based onrnhigh pressure acid leaching (HPAL) for extraction ofrnnickel and cobalt into solution, followed by solidrnliquid separation in a CCD circuit. However,rnflowsheets for separation and purification of thernnickel and cobalt diverge markedly. The existingrnplants have been commissioned with varyingrndegrees of success, with a variety of problemsrnranging from materials of construction to inadequaterndesign. While the process problems are notrninsurmountable, there is much room forrnimprovement.rnCurrently there are several new HPAL plants at thernfeasibility or financing stage. All of these havernadopted one of the existing flowsheets. Most of thernenhancements have focused on increasingrnautoclave size.rnIt is now time to assess the success and failures ofrnthe three existing plants and incorporate thisrnexperience in a design for productivity, efficiencyrnand reliability. Towards this end, this paperrndiscusses aspects of flowsheet optimization,rnmaterials of construction and engineering design.