Abstract
The aluminum industry generates large quantities of red mud during the beneficiation of bauxite ore. The red mud is disposed of as a waste in dry or wet form. Given the issues with its disposal due to the large volume and high alkalinity, many research groups and industries have examined the use of red mud for different applications. The use of red mud as a pre-catalyst for the cracking of hydrocarbon leads to hydrogen formation and carbon deposition. Our earlier studies have shown its activity for reaction with methane and the formation of magnetic materials containing iron, iron carbide, and nanocarbon species. In this study, two aspects were studied: one was methane cracking over red mud, modified red mud, and waste from a nailwork factory site and the other was the application of different hydrocarbons, including nitrogen-containing precursors over red mud. Preliminary characterization of the resulting carbon deposits was performed. The activity for methane cracking increased when the red mud was activated and reduced before the reaction. Nitrogen-containing reactants led to the formation of nitrogen-doped carbon nanotubes. The nitrogen amount and morphology varied with the precursor used and the reaction temperature. This is an attractive application with potential for further modification of the carbon deposits for other catalytic and electrochemical applications.