FULL LIFE CYCLE INTEGRATED AND RISK-BASED APPROACH FOR BAUXITE RESIDUE MANAGEMENT

The life cycle of bauxite residue disposal and management may comprise site selection, storage design and construction, operation, rehabilitation and closure. The processes of residue disposal operations may include neutralisation, thickening, transport, deposition, containment and consolidation.

This paper presents a full life cycle integrated and risk-based approach for bauxite residue management. In this approach, every stage of the life cycle and every operational process are considered together, as a whole, and within a context of sustainability. This multi-dimensional systems approach produces a good stewardship outcome with a solution that is technically sound, sustainable and lowest risk to society and the environment.

The main components of this approach include design for closure, risk management, rheological manipulation, integrated cost analysis and continual improvement. This approach provides a framework for safe, socially acceptable and environmentally responsible disposal and management of bauxite residue. It typically also results in the most costeffective outcome. Design for closure keeps closure in mind from day one of a storage development. Risk management involves identification of risks for all life cycle phases including post-closure, and managing and mitigating those risks to an acceptably low level throughout. Rheological manipulation requires an understanding of the tailings behaviour, particularly in the paste tailings regime, and how that can be best manipulated to optimise the overall tailings thickening, transport and deposition phases. Integrated cost analysis considers the cost curve for each stage of the life cycle, as well as jointly, so an optimum solution may be achieved. As new technologies emerge, and the social and environmental expectation is increasing, acceptable risk levels are getting lower and lower. Continual improvement is another key component of residue disposal and management and is an essential ingredient to our “social licence to operate” and therefore sustainability of the alumina industry.