New Zealand’s only smelter at Autoa looks to a settled future in Southland
Aluminium remains a key structural material used in multiple industries worldwide, and Tiwai Point is New Zealand’s only smelter.
A significant investment in new robot welding equipment shows that Rio Tinto is firmly committed to a future in the Deep South.
According to long-serving staff member Paul Cavanagh, Rio Tinto’s Tiwai Point has always been about its people, and that’s the driving factor in a recent upgrade and doubling of its robotic welding equipment.
“It’s about keeping people away from the load. People and safety first,” he said. Tiwai Point has used robotic welding since 1995, and this is the second upgrade since 2008 – but this time, the number of robots has doubled, along with the addition of an extra robot for loading heavy steel pins, a previously manual task. Cavanagh, the crew leader for the rodding process, says recent uncertainty was in the rear-view mirror, with the smelter securing a 20-year deal for electricity supply.
For some time, it was clear that the old system used to weld anode rods in aluminium production—around 550 are processed in a 24-hour period—needed to be replaced.
In the smelter’s reduction process, an anode is in the reduction cell for 24 days, where stubs can be damaged – either through process-related events or simple age.
Rods are rejected into the rod repair area, where the robot can weld all four stubs if necessary. Aluminium remains a key structural material used in multiple industries around the world, and Tiwai Point is New Zealand’s only smelter.
Cavanagh said the new system removed risk to staff. With one robot each side of welding tables it got people away from pinch points, hot zones and minimised risk from falls.
Made by Marlborough-based Autoa Robot Welding (formerly Autoline Automation), the new system is more precise, requires less maintenance and has improved the quality of the work.
It’s a longstanding relationship between the two companies—the smelter is a unique business and appreciates Autoa’s willingness to listen. According to Cavanagh, the final system is a custom design with input from the smelter, Autoa’s expertise, and “a bit of Kiwi ingenuity.” Challenges included programming, welding quality, and jig design, but Autoa “understood our entire process,” he said.
“If we go on a journey together you get a better result.”
In addition to safety, the robotic process makes for more skilled work, something that the company is focusing on as it looks to the future. They recruit from their community, with a focus on the mechanically minded willing to learn the skills. Today’s young people appreciate a more high-tech approach and upskilling opportunities, with manual labour less appealing and less safe.
After five decades in existence, Tiwai Point has many intergenerational staff – entire families have worked there, including Cavanagh and his father before him. He’s clocked up 40 years. He says it’s an exciting time, with modern processes and working environments attracting more women and more diversity in staff.
Fostering the family culture, along with safer work that challenges and excites staff is part of the mission for this company of national significance. “We’re looking to the future, creating a different environment that’s more attractive to apprentices, staff and contractors.”
Autoa’s innovative robotic solutions for aluminium smelting
Autoa Robot Welding has been at the forefront of advancing aluminium smelter operations worldwide, collaborating with industry leaders like Rio Tinto.
“Since the mid-1990s, our innovative robotic welding solutions have transformed hazardous manual handling tasks into safe, automated processes,” said Matt Fisher, director of Autoa Robot Welding. “We’ve proudly worked with aluminium smelters worldwide, from Dubai to Argentina, helping to remove operators from dangerous manual welding environments and improving efficiency.”
Unique to Autoa Robot Welding, the company has developed three different automation processes with more in development:
Superstructure bus bar repair: This process is for the automated repair of the bus bar face. The company has developed a ‘jig-less’ solution where the robot takes precise measurements and then pre-mills the face back with a 200mm diameter milling cutter, followed by continuous welding at approximately 45 minutes per pass to build the contact face back; this is followed by further milling to provide a clean unpitted contact face for the yoke to be bolted to, ensuring a robust and efficient repair.
Automated stub repair: This process automates the stubs on the anode yokes. Automatic and manual loading solutions have been developed for three-, four-, and six-pin yokes. “Our unique water-cooled welding torch provides full access around the stub, accommodating yokes on an overhead conveyor or in a horizontal position off the chain,” said Fisher.
Yoke transition joint repair: This process features dual robots with an aluminium and mild steel robot welder. It seamlessly welds the trimetallic clad (transition joint), removing the operator from this dangerous and dirty task.
“Autoa Robot Welding continues to innovate, developing new solutions to meet the evolving needs of the aluminium smelting industry, ensuring safety, efficiency, and precision in every project.”