Crystallization
Background
The crystallization program is concerned with understanding the fundamental processes of precipitation (nucleation, growth, aggregation and attrition) and what factors and impurities affect these processes. Ultimately, its aim is to control the precipitation process to the desired outcome (control of particle size and/or shape, mitigation of scale etc.). It remains one of our primary areas of expertise that is utilised in many of the NRI projects.
Above: Computer simulation of the phosphonate molecule, NTMP, on the barite (001) surface (side view).
Above: Potassium perchlorate crystal precipitated at 7°C.
Current Activities
The projects cover a broad spectrum of fields; ranging from mineral systems of iron, silica, barium sulfate and calcium carbonate to organic molecules such as lactose. The involvement of the group within the Parker CRC for Integrated Hydrometallurgy Solutions means that much work is relevant to hydrometallurgical processes. There is also a substantial crossover with the macrocyclic organic area that is used to great effect to develop new additives for various systems. Additionally, there are also two ARC funded projects in this area. Below are further details.
1. Iron and silica precipitation
- Iron and silica co-precipitation from industrial zinc solutions
Bill Richmond - Ferrihydrite: Fundementals of a natural nanomaterial
Bill Richmond, Nicole Gorham - Investigation of the effect of additives on silica precipitation in Bayer liquors
Franca Jones - Geopolymer concrete from regional waste streams
Kate Wright, Daniel Southam
2. Bio-inspired Crystal Growth
- Effect of additives on the precipitation of calcium carbonate
Mark Ogden, Mauro Mocerino - Investigation of lactose crystallization
Mark Ogden, Kristy Blyth
3. Scale formation fundamentals
- Investigating barium sulfate scale and how additives influence crystallization
Franca Jones - The solubility of sodium and calcium titanates in Bayer liquors and the formation of titanate scales
Franca Jones
4. Nanoparticle formation and molecular recognition
- Formation of iron nanoparticles
Bill Richmond and Dr Mitch Loan (MSSI, Univerisity of Limerick) - Understanding the role of molecular recognition in the formation of barite nanoparticles in the presence of additives
Franca Jones
5. One-on-one industry projects
In all of these projects there is an emphasis on understanding the fundamental mechanisms of crystallization and using state of the art techniques such as AFM and computer modelling.
Funding
Most of the funding for this program comes from CRCs or industry (Parker CRC for Integrated Hydrometallurgy Solutions, CRC for Sustainable Resource Processing, Dairy Australia). ARC funding has been also successfully obtained for two iron projects.
Above: Gypsum crystals viewed under an optical microscope.
Above: Calcium oxalate crystallized in the presence of aspartic acid.