hydro aluminum ingots
A new process has the potential to use up to 90 percent less energy than conventional recycling in the creation of aluminum extrusion ingots like these made at Hydro’s Karmøy, Norway, plant.
Photo courtesy of Norsk Hydro ASA; taken by Bård Gudim

Hydro piloting energy-saving aluminum recycling method

Norway-based metals producer says the technology it is testing cuts energy consumption up to 90 percent.

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January 13, 2021

Oslo-based energy and aluminum producer Norsk Hydro ASA (Hydro) says it is working with a Norway-based startup firm called Nuvosil on new technology for the recycling of aluminum and silicon. The pilot project could lead to a method that reduces processing costs significantly and energy consumption up to 90 percent, say the two firms.

The consortium partners developing the technology include Hydro and Nuvosil, supported by research and industrial partners Norway-based SINTEF, the Norwegian University of Science and Technology (NTNU), Austria-based Cemtec and Germany-based Reifenhauser, who are all part of the Norway-based Low Energy Recycling (LER) project.

The core element of the technology is a screw extrusion unit. During the project, the partners intend to build, test and qualify a commercial-scale version of the extruder, in addition to confirming scalability of other associated components and process steps.

“We are very encouraged to kick off the industrialization of the Hydro laboratory screw-extruder technology, which has been tested in a range of R&D projects in close collaboration with NTNU in Trondheim, Norway,” says Trond Furu, research manager in Hydro’s Corporate Technology Office.

Norwegian government agency Enova has been following the development of LER technology and has supported the project with $1.1 million in funding, says Hydro.

“The technology greatly reduces energy consumption and significantly increases the recycling rate. Enova believes that technology of this type is needed to reach the low-emission society and eliminate greenhouse gas emissions by 2050,” says Ståle Kvernrød, senior adviser at Enova.

“We are very pleased with the support from Enova,” says Bjørn-Olav Brelin, CEO of Nuvosil. “Even with the very promising operational and financial prospects of the LER technology, Enova’s financial contribution and risk-sharing has been crucial for the realization of this project.”

The technology is expected to be tested in one or more of Hydro’s plants in Norway, with production of Hydro CIRCAL, a recycled-content extrusion ingot, as one potential application area.

The project will conduct one trial using scrap automotive wheel rims and process scrap from machined primary foundry alloys. The other trial will use a combination of aluminum scrap with silicon from the production of solar panel wafers.

Both trials will employ the screw extrusion process, in which the aluminum scrap alone or in combination with the silicon pellets are fed into a screw-driven extrusion press.