Moisture control is critical for safe and economic iron ore production and export. Moisture must be high enough to suppress dust, yet below the level where material handling difficulties occur and below the transportable moisture limit (TML) for safe shipping. There are substantial economic benefits to minimising iron ore moisture, eg, a 1% reduction in moisture content from 9-8% represents potential savings of $63M based on freight costs from Australia to China (680 Mt production at a typical freight cost of $8/t). For Brazil, with a higher freight cost of approximately $20/t, the potential savings for 340Mt of iron ore are $81M. The key project objectives are: Stream I: • Develop a global moisture analyser calibration matrix covering the range of properties of sponsor iron ores, including ore mineralogy variations between hematite, goethite. This would be implemented on the Scantech TBM system, and may potentially be applied to non-Scantech analysers depending on compatibility of the analyser’s operating principles and software; • If possible, develop an on-line mineralogy measurement system for iron ore on conveyor belts and integrate this with the existing TBM (or CM100) system; • Develop measurement of mass per unit area (MPUA) as an alternative enhancement to increase the accuracy of moisture measurement using the TBM, and potentially indicate changes in ore mineralogy; • Supply a measurement of through-belt ore moisture, and potentially the secondary measurement of the surface moisture, for input into control systems; • Trial a prototype system at one or more sponsors’ sites. Stream II: • Determine the mode and rate of moisture migration for each sponsor ore sample; • Define moisture migration characteristics and associated curves for each ore, which will be compared to Sponsor material handling systems to identify whether existing belt oscillations or train wagon/routing vibrations are appropriate or helpful for moisture reduction; • Conceptual design of moisture reduction/control system(s) to exploit the moisture migration measured for the range of ore types.
Dr Tom Honeyands