Sustainable Optimization of Lightweight Aggregate Production from Bauxite Residue via Nonlinear Programming

Area of Science:

• Materials Science
• Civil Engineering
• Waste Management

Background:

• Bauxite residue is an industrial byproduct with potential for material development.
• Lightweight aggregates are crucial for sustainable construction materials.
• Optimizing aggregate composition requires advanced modeling techniques.

Purpose of the Study:

• To develop lightweight aggregates from bauxite residue and clay mixtures.
• To determine the optimal composition using a nonlinear programming model.
• To evaluate the physical and structural properties of the developed aggregates.

Main Methods:

• Mixture design using nonlinear programming.
• Characterization via TGA/DTG/DSC, X-ray diffraction, and SEM.
• Physical testing: apparent density, porosity, and water absorption.

Main Results:

• Bauxite residue incorporation led to amorphous, porous phases and reduced aggregate density.
• Optimal composition identified as 30.50% bauxite residue and 69.50% clay.
• Optimized aggregate exhibited density (0.78 g/cm³), porosity (14.54%), and water absorption (14.05%).

Conclusions:

• The nonlinear programming model effectively optimized lightweight aggregate composition.
• Bauxite residue is a viable, sustainable alternative for producing construction materials.
• Developed aggregates meet lightweight criteria, offering environmental benefits.