Influence of GGBS on Strength of Red Mud Stabilized by Alkalination Process

Abstract

Industrial process generates huge amounts of industrial by-products which occupy large stretches of land surface causing environmental pollution. Red mud is the by-product of aluminium industries, generated through the Bayer process for extraction of aluminium by digesting with high concentration of sodium hydroxide. Its properties make it extremely difficult to work with and to dispose it off. The major constituents of red mud are Fe2O3, Al2O3, TiO2, SiO2 and Na2O. Red mud is a highly alkaline waste. Thus, by adding small amount of alumino-silicate rich material, it can be solidified. With a view of the above, this research is aimed to stabilize the red mud by activating it by addition of ground granular blast furnace slag (GGBS). Additionally, the effect of addition of higher doses of alkali that is NaOH has been studied. The compaction characteristics have been studied for each combination of GGBS and NaOH content to the red mud. Moreover, the mechanical strength of the same has been studied for different curing periods. Simply addition of GGBS to the red mud without any alkali results in an increase of compressive strength. The unconfined compressive strength test result reveals that GGBS and NaOH content are the major influencing parameters.