Marjorie Valix - Biomolecular Engineering

Using microbiology in developing sustainable technologies for mineral processing and waste management

Associate Professor Valix aims to harness microbiological approaches in the management of waste and recovery of base and precious metals from low-grade ores. Such processes have tremendous potential as extracting and recycling technologies, and, as well as being environmentally sound, have the potential to lower operational costs and energy requirements.

Valix’s team has conducted leading research in the creation of the fundamental science of using microbes and their metabolic products to degrade highly stable mineral oxides and waste polymers. Besides their industrial application to raw material supply, microbial processes have the potential to extract metals from metal-laden wastes and to recover chemical and energy resources from carbon-based wastes. Valix has made the following advances:

• Initiated the first research in the use of fungi micro-organisms and their metabolic products in bioleaching of oxide minerals in Australia.
• Discovered metabolic products, processing methodologies and process configurations that facilitate tenfold increases in the rate of bioleaching, multiple recycling of pregnant acidic solutions in the leaching process, and selective bio-based recovery of nickel and cobalt.
• Transformed bioprocessing technology by identifying and adapting new organisms that outperformed their wild version by overproducing active leaching reagents and demonstrating tolerance to extreme conditions, for example high temperatures.
  Pioneered the ‘biohydropyrolysis’ of polymeric wastes, a novel method to harness the ability of organisms to provide hydrogen and enzymes that weaken polymeric bonds, thereby inducing their low temperature degradation. This significant breakthrough will enable the practical application of this new recycling technology.