Mineral Phase and Physical Properties of Red Mud Calcined at Different Temperatures

الملخص EN

Different characterizations were carried out on red mud uncalcined and samples calcined in the range of 100°C–1400°C.

In the present paper, the phase composition and structural transition of red mud heated from room temperature are indicated by XRD, TG-DTA, and SEM techniques.

The mean particle diameter, density, and bond strength of these samples also have been investigated.

The results indicate the decomposition of gibbsite into Al2O3 and H2O between 300°C and 550°C and calcite into CaO and CO2 in the interval of 600–800°C.

Tricalcium aluminate and gehlenite are formed in the range of 800–900°C.

Combined with the SEM images, the results of physical property testing show that the particle size and the strength each has a continuous rise during the heat treatment from 150°C to 1350°C.

But the value of density will undergo a little drop before 450°C and then increases to a higher value at the temperature of 1200°C.

These obtained results provide an important base for the further studies of comprehensive utilization of red mud.