The Parker Centre has strong support from the alumina industry and allied companies. Alumina producers and engineering companies/industry suppliers make up 12 of the Centre’s 19 Industry Participants.

The five principal alumina companies in Australia – Alcan International, Alcoa World Alumina, Billiton Aluminium Australia, Rio Tinto Aluminium and Queensland Alumina – are all Industry Participants in the Parker Centre. Overseas alumina producers Aughinish Alumina and Norsk Hydro are also Industry Participants. Collectively these seven companies produce approximately 55% of the world’s alumina.

The Bayer process for extracting alumina (aluminium oxide) from bauxite ore produces the majority of the world’s alumina. The Bayer process involves the dissolution of the aluminium oxy-hydroxide minerals in bauxite ore using hot concentrated caustic solutions. The aluminium-laden liquor is separated from the waste solids (primarily iron oxides and silicates) before the aluminium is recovered as gibbsite (aluminium hydroxide, also called alumina trihydrate) by seeding and cooling the liquor. The final step in the process is calcination of the gibbsite (Al₂O₃.3H₂O) to alumina (Al₂O₃) by heating.

Being a mature industry, there is an on-going need for process improvements and new technologies. The alumina industry had considerable input into the Parker Centre’s current alumina project portfolio, which was designed to address six of the 12 areas identified by the industry in the Alumina Technology Roadmap as priority areas for R&D to 2020.

The Centre’s alumina research includes CRC-funded research projects; pre-competitive, multi-sponsored AMIRA projects (the P266E "Improving Thickener Technology" project, the P507C “Thermodynamic Characterisation of Organics in Bayer Liquor” project and the P521C “Developing a Mathematical Model of the Effect of Solid Phase Oxalate on Gibbsite Secondary Nucleation” project) and one-to-one company-specific projects.

This research involves around 40 full-time equivalent research staff, drawn from all four of the Centre’s Research Participants and a range of disciplines. These researchers include chemists, fluid dynamicists, chemical engineers, process engineers and physicists. They are supported by a unique array of Bayer-specific and general research equipment.

ALUMINA RESEARCH CAPABILITIES

• Characterisation of bauxite mineralogy
• Bauxite processing assessments
• Impurity removal technologies
• Bayer process chemistry
• Studies of solution properties and solution chemical species
• Flocculation
• Characterisation of surface processes: surface properties, adsorption behaviour and inter-particle forces
• Thickener design and performance issues
• Alumina product strength and quality
• Precipitation technology
• Computer modelling: molecular modelling, modelling using computational fluid dynamics and process models
• Environmental issues, including residue treatment.

ALUMINA RESEARCH AREAS
The Centre’s alumina research includes CRC-funded projects covering the red-side and the white-side of an alumina refinery, solid-liquid separation, impurity issues, fluoride speciation, scale and environmental issues (follow the links below for further details on each project):

• Research in the Bayer Red-Side Technology project includes:
  - bauxite characterisation
  - bauxite beneficiation
  - predicting bauxite processing behaviour
  - desilication and digestion of bauxite ore, flashing and lime chemistry
  - process options for high-silica bauxites, including acid routes
  - thermodynamics of acidic aluminium/iron solutions relevant to acid processing routes.
  
  
• The Bayer White-Side Technology project focuses on:
  - options for increasing gibbsite precipitation yield
  - precipitation kinetics models describing the relationship between precipitation rates and process variables
  - modelling inhomogeneously mixed industrial precipitators
  - secondary nucleation and management of fines
  - alumina strength and breakage behaviour (product quality)
  - simulation of a precipitation circuit.
  
  
• The Solid-Liquid Handling project involves research on:
  - aggregation processes
  - thickening of residue
  - relating suspension properties, solution properties and reagent adsorption to inter-particle interactions and hence dewatering behaviour
  - modelling of all aspects of the thickening process
  - dewatering issues in other markets.
  
  
• The Impurity Issues project focuses on:
  - sodium oxalate crystallisation and stability
  - removal strategies for organic impurities
  - removal strategies for inorganic impurities
  - fluoride speciation in Bayer liquors
  - scale prevention or minimisation.
  
  
• Research in the Bayer Environmental Issues project includes:
  - bauxite residue disposal and re-use options
  - understanding causes of emissions (eg odours, trace metals and dust) and formulation of options to control such emissions.
  
  
• The Framework for New Technologies project focuses on:
  - factors affecting community reaction to the proposed introduction of new hydrometallurgical processes
  - communication with the community about new processes.

The Centre also undertakes a wide range of other projects with companies in the alumina industry, many of which are confidential projects.

INDUSTRY BENEFITS
The potential benefits to the minerals industry of the Centre’s alumina research include:

The Centre's alumina researchers work in:
CSIRO Minerals' Alumina Production Program
Murdoch University's School of Electrical, Energy and Process Engineering
Murdoch University's School of Chemical and Mathematical Sciences
Nanochemistry Research Institute (Curtin University)
Curtin University's Department of Applied Chemistry
Centre for Social Responsibility in Mining (University of Queensland).

ALUMINA MARKET LEADER: DR CHRIS VERNON