Red mud of aluminium production waste as basic component of new construction materials

Abstract

The work presented here shows the possibility of using the red mud waste from the Bayer process used for aluminium production as the main component of new construction materials. It describes some recent experiments lasting 180 days as well as some 1 year old samples. The best part of materials used are industrial wastes, but some of them contain small (no more the 2%) additions of CaO or Portland Cement (PC) to increase the strengthening rate of the samples. The high strength values of these materials allow their use as new materials for road and airfields bases, levee core, dumps, foundations, etc. They can also be used to make bricks, tiles, and similar items. In addition to the economic factors, these materials are very easy to use and no new residues are generated. The results of the heavy metal leaching tests, not included in this paper, show very low levels of their leachability in acid solutions, far below the demands of the Spanish environmental standards. This can be explained by the strong chemical binding of heavy metals in practically insoluble chemical compositions.