Crystallisation and precipitation
Crystallisation is a separation and purification process used in the production of a wide variety of materials ranging from bulk commodities to specialty chemicals and pharmaceuticals.
The crystallisation process commonly involves simultaneous occurrence of a number of crystallisation mechanisms.
Our research focus includes:
- improving fundamental understanding of crystallisation mechanisms such as:
- nucleation – generation of new crystals in solution
- crystal growth – deposition of solute from solution onto crystal surfaces
- agglomeration – aggregation and cementation of smaller crystals to form larger agglomerates
- advancing experimental techniques and tools for monitoring and quantifying crystallisation mechanisms
- developing numerical procedures for the estimation of crystallisation kinetics and modelling of crystallisation processes
- integrating fundamental understanding of physicochemical processes with mathematical modelling to address complex process challenges
- developing numerical models of plant-scale crystallisers and crystallisation circuits.
Our researchers use a range of specialised laboratory-scale crystallisation equipment to generate experimental crystallisation data under different operating conditions.
This equipment includes:
- Taylor-Couette crystalliser
- semi-continuous stirred tank crystalliser
- batch controlled-cooling stirred tank crystalliser
- Coulter Counter and AccuSizer particle size analysers
- optical and scanning electron microscopy
- automated titrator and other specialist on-site analytical equipment.
Our crystallisation and precipitation research has resulted in:
- an improved understanding of gibbsite precipitation from caustic-aluminate solutions.
- development of mechanistic models for gibbsite precipitation kinetics (through the AMIRA P521 project)
- quantification of the impact of process operating conditions and impurities on gibbsite precipitation kinetics
- development of crystallisation process models and simulation tools to facilitate rigorous plant optimisation.