A unique eddy current separator extracts valuable metals from the fly ash from boilers.
A unique eddy current separator extracts valuable metals from the fly ash from boilers. Photo: Patrik Olsson.

Ragn-Sells and Norditek increase recovery rate of metals from fly ash 

Norditek’s unique eddy current separator enables Ragn-Sells’ Heljestorp treatment plant to increase the recovery rate of metals in fly ash. “Through our partnership with Norditek, we can extract metals from even the finest fractions, including precious metals,” says Bernt Jansson, Section Manager.

30 Jun 2021

Ragn-Sells’ Heljestorp treatment plant is located outside Vänersborg and handles large volumes of fly ash from boilers. Through a close partnership with Norditek, which provides machines and concepts that recycle, process, and transform materials, the handling of fly ash has been developed in recent years. The aim is to continuously increase the recovery rate of metals.

– To get the most out of our technology, we need extended, regular dialogues and Ragn-Sells has really invited us to do that. We have been able to study their production systems to understand how they work, which is an important key in this partnership, says Daniel Carlberg, CEO of Norditek.

Maximises recovery rate from fly ash

In the spring, Norditek delivered an eddy current separator to Heljestorp, which means that the recovery rate for fly ash is now increasing further. It is now part of a unique overall solution.

– We also supplied the previous technology and are now integrating it with this new eddy current separator. The result is that we are maximising the recovery rate.

What the eddy current separator adds to the process is that it can extract metals from even the finest fractions.

– When we process the fly ash, we put it through a sieve that separates the material into three different sizes. Previously, we were unable to extract metals from fractions smaller than three millimetres, but the new eddy current separator now lets us do that.

– Now we can separate out metals such as aluminium, zinc, lead, and even precious metals such as gold and silver from even the finest fractions, which increases the recovery rate, says Bernt Jansson, Section Manager at Heljestorp.

Metals are extracted in three steps

Daniel Carlberg explains how the technology works.

– The first step is a feeder belt with rotating fingers that spreads the material laterally into a very thin bed, a monolayer.

In the next step, the material is fed onto an acceleration belt that extends the length of the material and an end roller magnet at the end of the belt picks out the magnetic material.

– The non-magnetic material is extracted in a third step with an eddy current magnet that has a high intensity magnetic configuration. This is exclusive to Goudsmit’s magnetic rollers, and generates extremely high magnetic forces that enable the recovery of small and weakly magnetic NF particles such as precious metals, says Daniel Carlberg.