Anodisation sludge as secondary resource to mineral wool

Important results from the project

The scope of the project was to investigate the possibilities to use the anodizing sludge as a secondary raw material in the mineral wool production. The aim has been to clarify whether anodizing sludge technically can be used as a secondary raw material for the mineral wool industry or not. The project shows that it is technically possible to make strong briquettes that can be used in the cupola furnace in mineral wool production. Experiments on an industrial scale are needed to investigate the possible effect on emissions and residual materials.

Expected long term effects

It is shown that it is technically possible to add anodizing sludge in briquettes and at the same time maintain a sufficiently high strength for mineral wool production. How to add the sludge and the amount of added sludge must, however, be optimized for industrial production. The performed analysis of sustainability and economy show good possibilities to move further on a larger scale. An industrial implementation of the result of the project can reduce the aluminium industry´s quantities of deposited sludge and increase the amount of secondary raw material in the mineral wool industry

Approach and implementation

Characterization of the anodizing sludge was carried out and the sludges were used as an additive when manufacturing briquettes on a pilot scale. The briquettes were evaluated concerning strength and manufacturing. In addition, a study of alternative uses of the anodizing sludge, a cost study and a sustainability analysis were performed. The project was carried out in close collaboration between the research institute and the participating companies and within the project four workshops have been held. During these, partial results have been presented and discussed.