Stage 2, Washer Bridge Support Upgrade

Overview

Located 10 km north-west of Gladstone, the Yarwun Alumina Refinery produces nearly 3 million tonnes of alumina annually. To enhance the structural integrity of the tank structures, Pructon was engaged to replace supporting members that provide foundational support to the centre tank top, which is also supported by the walkway bridge above. This installation has significantly increased the safety and longevity of the tank, which is crucial for holding the bauxite sludge in the aluminium extraction process. A shutdown period was necessary, with 24-hour shifts implemented to ensure rapid resumption of operations.

Scope of Work

• Sandblasting: Sandblasted all areas requiring new equipment installation to prepare surfaces for coating.
• Non-Destructive Testing (NDT): NDT technician conducted ultrasonic testing to ensure no defects, with all tests passing without impurities.
• Installation of Ring Beam: Installed a 6-part ring beam, which was welded, inspected, and tested for quality, location, and purpose.
• Welding Techniques: Utilised Flux-Cored Arc Welding (FCAW) for the installation of both top and bottom supporting lugs, ensuring precise alignment.
• Load Cell Fitting: Verified that the load cell was fitted to a tolerance of 0.05 mm.
• Internal Stiffener Plates: Installed and welded internal stiffener plates, which were subsequently inspected for quality.
• Comprehensive Testing: All components underwent ultrasonic testing and Magnetic Particle Inspection (MPI), achieving a 100% success rate.
• Final Coating: Completed sandblasting and painting of all components, with quality checks implemented throughout the process.
• Pipework Modifications: Modified existing pipework to accommodate the new supporting members.

Outcomes and Benefits

• Reduced Inspection Frequency: Decreased inspections on the structural integrity of the tank top, leading to operational efficiencies.
• Increased Structural Integrity: Enhanced structural integrity of the tank top, allowing for better load management.
• Load Stress Monitoring: Improved ability to read load stresses on the tank, ensuring safe operational conditions.
• Peace of Mind: Assurance regarding steel integrity following successful lamination scans and ultrasonic testing.
• Capacity Assurance: Tanks are now capable of comfortably holding their design capacity.
• Maintenance Readiness: Area left clean and prepared for any future mechanical maintenance.