Production of Aluminum Sulfide through Carbosulfidation Utilising H2S

Indirect carbothermal reduction of alumina for the production of aluminum utilizes different reducing agents to convert alumina into intermediate aluminum compounds. In the present study, the carbosulfidation route for aluminum production utilizing H₂S(g) as the reductant and sulfur source has been investigated, in particular the formation of Al₂S₃ in the first step of the process. The results of the thermodynamic analysis predicted that conversion of Al₂O₃(s) to Al₂S₃(l) significantly increases above 1400°C at 1 atmosphere pressure. Experimental investigations were carried out at temperatures of 1100 to 1500°C using dilute H₂S(g) gas in argon. The reaction products were analyzed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), inductively-coupled plasma absorption emission spectroscopy (ICP-AES) and chemical filtration. The X-ray diffraction results confirmed the presence of Al₂S₃(s). Percentage of conversion from Al₂O₃ to Al₂S₃ was found to be over 80% at 1500°C.