Hydrogen-metallized slag - refinement and uses - HAGGIS

Purpose and goal:

The long-term goal is to recycle slag in a metallized form. We have taken steps towards this goal as we have evaluated the concept on a small scale, with promising results, which was the goal of the project. However, it is not easy to understand how separation and other optimizations can be employed in the best way, a lot of work remains here.

Among other things, we should investigate whether the slag can be pre-treated in some way to facilitate the metallization. Already when the slag is generated in production, it would be possible to pre-treat it. Expected results and effects:

After repeated tests, we can say with certainty that the concept works, for 1/2 tested slags. Possibly the concept works for the second slag, but more tests are needed to ensure this.

For the slag on which the concept certainly works, there are metallic particles in the material after hydrogen metallization. The part that is not metallized constitutes a new slag, which, according to preliminary tests, does not leach environmentally hazardous metals into water. Approach and implementation:

The small scale tests were performed successfully at Swerim, with subsequent characterization at Chalmers. The characterization proved to be rather difficult as not all techniques could distinguish the metallized material from the untreated material. Mass loss of the material during metallization turned out to be a good indicator, which correlated with the content of reducible oxides in the material. Microscopy, using SEM, of cross sections enabled composition analysis.