Hot trials at Swerim with a focus on salt

The aim of the trials has been clear: salt from aluminium smelting at Stena Aluminium will be recovered and recycled to aluminium production. In addition to the salt, the treated slag will also be useful. The expectation is that this can be used in the steel industry. 

The trials are part of the four-year, EU-funded Horizon project, RecAL. In total there are 19 project partners from throughout Europe, but Swerim, Stena Aluminium and British Altek Europe have partnered specifically for this particular piece of the puzzle. 

"Coming here is always fascinating and impressive. Here, engineering specialists with the right expertise and industrial experience carry out the research in pilot scale," says Ola Falk, process development manager at Stena Aluminium. 

Today, the salt slag, a residual product from aluminium production at Stena, is sent to treatment facilities in Central Europe, where the salt is recovered for recycling back to production. 

"Of course, it would make better sense, both environmentally and economically, if we could do the recovery and recycling here, and also produce an additional product that would be of value to the steel industry." 

An intensive week of trials 

Technicians in protective gear oversee the process. Heated to 1600 degrees Celsius, the treated slag is a brilliant yellow. The aim is for this to subsequently be re-used in the steel industry. 

"Here at Swerim, after the trial week, work will focus on testing the quality of the treated slag and finding ways of upgrading it as a product for industry," explains Ulf Sjöström, project manager at Swerim. He also notes that it is an intensive week for personnel at the research institute. 

"We have round-the-clock manning for about a week and everything is going according to plan." 

Also on hand for the week of trials are representatives from the British company Altek Europe, a major provider of services to the aluminium industry. They are here to see how the technical solutions for recovering the salt can be further improved, since trials will be scaled up from pilot to industrial scale. The quality of the salt will also be tested. 

"I will be taking samples of the salt from the trials in Luleå to the laboratory in the UK," says Gigi Nicolson, chemical engineer and salt specialist in the aluminium industry. Considering her normal work environment, the visit to Swerim has made a big impression. 

"Since I work in a lab, it is rather unusual and quite impressive to see how research is done in a near-industrial-scale setting." 

Information about the project

For more information about the RecALom project, contact:  

• Ulf Sjöström, ulf.sjostrom@swerim.se<mailto:ulf.sjostrom@swerim.se> 

Photo: From left: Gigi Nicolson, Altek Europe; Benjamin Brash and Ola Falk, Stena Aluminium; Ulf Sjöström, Swerim and Adele Forrest, Altek Europe. Absent: Rob Morello, project manager at Altek Europe. 

Photo 2: Technicians in protective clothing control the process where the purified slag is heated up to 1600 degrees.