Project Status: Complete
Project Participants: Alcoa, BHP Billiton, Rio Tinto, University of Queensland, AMIRA, RWTH Aachen University, University of Nottingham
Project Leader: Bruce Fraser (AMIRA) and Peter Holtham (University of Queensland)
Water is ubiquitous in mineral processing. Grinding, flotation, gravity concentration, dense medium separation and (by definition) hydrometallurgical processes all use water in great quantity.
Water can no longer be considered the 'free' and inexhaustible resource that minerals engineers have been able to rely on in the past. Many ore deposits exist in arid areas, and others are worked in areas in which there is severe competition for water from agriculture, other industries, and local populations. Water supplies for mining will be increasingly compromised in the future, reducing availability and increasing cost. There is also a need to meet more demanding regulatory standards in the quality of the process water that is disposed of to the environment. These pressures are leading to an increasing emphasis on saving water in mineral processing operations, including its more efficient recycling.
However there may be a radical solution to these problems - the use of dry or near-dry processing technologies, for which the demand for water is small or zero. The aim of this project was to determine the current status, immediate future, and dominant issues associated with large scale dry processing.
The project provided sponsors with a clear summary of the current status of dry processing worldwide: equipment used, ores treated (type and size distribution) and tonnage treated. It identified potential new dry or reduced water processing technology still at pilot scale that might have large-scale application. Limitations and benefits of each technique relevant to various commodities and applications will be identified. The project also identified the most promising process routes and recommend the further opportunities necessary for further development of promising technologies, process flow sheet development and ore characterisation.