In today's world, where achieving the goal of sustainable development has become a focal point of many companies' strategies, responsible waste management and the implementation of a zero waste policy is a milestone on the way to success.
GreEnergy AS, supported by local aluminium producer Hydro Aluminium AS Høyanger, Innowation Norway, Sparebanken Vest and induction technology provider Inductelec Ltd, has started a project to find a solution to close the recycling loop of aluminium production by recovering and recycling copper from cathode bars using induction powered by low-cost renewable energy sources.
The aluminum is produced extracting it from the aluminum oxide through an electrolysis process driven by electrical current. The process in carried out in the alumina reduction cell.
The main components of the alumina reduction cell, on the process side, are the carbon anode and the pot, usually called "cathode".
At the bottom of every cathode there are slots that accommodate a collector bar, called cathode beam.
Cathode beams are made of steel or iron with a special pocket into which a copper bar is pressed to improve conductivity.
As every element of the cell, the cathode also has its durability. It is assumed that the pot should be replaced every five years. Cathode beams are also replaced at the same time.
Currently, cathode beams, as well as whole cathodes, from demobilized cells are considered as waste and are transferred to landfill or external waste treatment facilities.
This approach creates environmental problems for the smelters.
The long term goal of the project is to help the aluminum industry have closed their recycling loop of waste from aluminum production.
GreEnergy wants to separate the two metals by using inductive technology. After separation, the metals could be returned to aluminium production or recycled.
The whole process would take place locally in Hoyanger in Hoyanger Industril Park (HIP), which is located near Hydro smelter, and would be powered entirely by renewable energy - a local hydropower plant.
The scope of the project is to design the process of treating the cathode beams that arise as a waste after the replacement of the cathode in an alumina reduction cell.
Currently, the project comprises two phases, the feasibility phase and the concept phase.
The objective of the feasibility phase is to propose and test the process of recovery of copper and steel from the cathode beams.
In the concept phase, based on the results, analyses of the profitability of the process implementation on the industrial scale will be carried out, together with preparation of the process design basis for this implementation.
Project implemented with own funds, funding from Innovation Norway and Sparebanken Vest