SPL‐CYCLE: Closing the loop of the Spent Pot‐line (SPL) in Al smelting process
Research Project, 2018 – 2021

Each ton of aluminium produced in Al smelters generates approx. 20kg of hazardous waste, which is a mix of the carbon lining and the refractory lining, known as "spent pot lining" (SPL). Worldwide aluminium production in 2016 was approximately 59 million tonnes, corresponding to the generation of 1.18 million of tonnes of SPL. The current practice of the waste management of hazardous SPL is landfilling or incineration, which costs aluminum producers on average 200 EUR/tonne (240 million EUR annually on a global level).

The project presents a novel zero waste technology for the recycling of spent pot lining (SPL) from aluminum production, consisting of four main separation on processes (preparation, extraction, flotation, and refining) in order to achieve the quality of products needed by end‐users. The final products will be used either in aluminum production (recovered carbon and fluoride slats) or will be sold to the refractory industry or the construction industry (recycled refractory residues). A pilot demonstration of the operability of the system will be constructed at the company in Slovenia, with the aim of optimizing and valorizing the technology. Additionally a reliable business model will be developed enabling the next steps to commercialization.

The innovative technology itself and the new sustainable approach will therefore represent a new circular economy business model for aluminum producers with the complete elimination of waste deposition and incineration costs.


Burcak Ebin (contact)

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Martina Petranikova

Chalmers, Chemistry and Chemical Engineering, Energy and Material


Aluminium of Greece

Athen, Greece

Flemish Institute for Technological Research

Mol, Belgium

National Technical University of Athens (NTUA)

Athens, Greece

Scientific Research Centre Bistra Ptuj

Ptuj, Slovenia

Slovenian National Building and Civil Engineering Institute (ZAG)

Ljubljana, Slovenia

University of Ljubljana

Ljubljana, Slovenia


Freiberg, Germany


EIT RawMaterials

Project ID: 17141
Funding Chalmers participation during 2018–2021

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