Chapter 3 - Use of red mud as advanced soil stabilization material

Abstract

Worldwide, alumina is extracted from the bauxite ore through the Bayer process which generates red mud, also called “bauxite residue,” in large quantities. Red mud consists of oxides of unreacted iron and titanium, sodium aluminosilicates, and nonextracted alumina. It is highly alkaline and is characterized by very fine size. Disposal and storage of bauxite residue have a marked environmental impact, and hence, its utilization has become an absolute necessity. Soil stabilizers are the materials used to bind the soil particles together for better water resistance and to improve the physical and chemical properties of soil. Due to its specific nature, red mud has emerged to have a probable application as an advanced material in soil stabilization. In this context, the proposed chapter consists of the use of bauxite residue in heavy metal immobilization in agricultural soils, remediation of heavily contaminated acidic soils, and fly ash stabilization in the application of embankment material for road construction. Along with the chemical composition and physical properties of red mud, research fundamentals applied by investigators worldwide, and their findings in the application of red mud as a soil stabilizer have been compiled and explained.