Project Status: Complete. Further work carried out under the 4C2 project.
Project Participants: CSIRO, Rio Tinto, One Steel, CRC Salinity, Department of Conservation and Land Management WA
Project Leader: David Langberg (CSIRO)
The metallurgical industry faces increasing pressure to reduce the emissions of greenhouse gases (GHG) from the production of metals. The substitution of fossil carbon by renewable carbon from biomass such as charcoal has the potential to radically reduce the net carbon emissions to the atmosphere from metallurgical processes. At the same time, the past practice of large scale removal of the native perennial tree cover to establish farmland has led to salinisation problems in Australia. The broad acres of shallow rooted, annual crops has caused the slow, progressive rise in the water table, which has salinised and degraded the soil where the subterranean water has high salt levels. A planting program of short harvest cycle trees (oil mallee) has commenced in the wheat belt of WA to lower the water table. This will produce large quantities of woody residues, which could potentially supply low cost charcoal to the metallurgical industry.
This project established the technical basis for determining the extent to which fossil carbon can be replaced by charcoal as the reductant in established and emerging high temperature metallurgical processes (eg rotary kilns, bath smelters). A literature review summarised the available knowledge on the carbon requirements for a range of metallurgical processes, and the extent to which they are likely to be met by charcoal. Experimental work demonstrated the performance of selected charcoals in tests relevant to the metallurgical processes. A marketing exercise established the industrial interest in using charcoal in metallurgical processes.
The research objectives were to:
This project demonstrated that charcoals produced from oil mallee trees are suitable reductants for use in rotary kilns (Becher process), and for bath smelting processes (HIsmelt process).