Document Type : Research Article

Authors

• Hossein Haddady ¹
• Nader Setoudeh ²
• Raziye Hayati ¹
• Abbas Mohassel ³

¹ Materials Engineering Department, School of Engineering, Yasouj University, Yasouj, Iran

² Materials Engineering Department-School of Engineering-Yasouj University- Yasouj- Iran

³ Materials Engineering Department, School of Engineering, Yasouj University, Yasouj, Iran (retired)

Abstract

The kinetic assessments for calcination reaction (dehydration reaction) of the bauxite sample was studied in this article under non-isothermal condition. After crushing and grinding the bauxite sample, the chemical analysis of the sample was obtained using x-ray fluorescence (XRF) method. The X-ray diffraction (XRD) patterns identified boehmite, hematite, and silica (silicon oxide) as the primary phases in the bauxite sample. The calcination reaction of the bauxite sample was evaluated using simultaneous thermal analysis (STA). The results of STA analysis indicated that the calcination reaction occurred at approximately 537 °C, with the final mass loss reaching about 13%. When the bauxite sample was heated to 600 °C in an air atmosphere for one hour, the boehmite phase decomposed, but the aluminum oxide phase did not fully crystallize. Kinetic evaluations were conducted using thermogravimetric analysis (TGA) data (STA analysis) under non-isothermal conditions, employing the Coats-Redfern method. The kinetic assessments revealed that the activation energy for the calcination reaction of the bauxite sample containing the mineral boehmite is approximately 198 kJ/mol, and the reaction follows the Crank equation of the diffusion models.

Keywords

• Aluminum oxide
• Activation energy
• Bauxite
• Boehmite
• Calcination reaction

Main Subjects

• Manufacturing planning, optimization, and simulation