Synergistic extraction and separation of valuable elements from high-alumina fly ash with carbochlorination method
A novel process was proposed for synergistic extraction and separation of valuable elements from high-alumina fly ash. A thermodynamic analysis revealed that to achieve effective carbochlorination,it is crucial to conduct carbochlorination of the fly ash within the temperature range from 700 to 1000 ℃. The experimental results demonstrated that under the optimal conditions,the carbochlorination efficiency for Al,Si,Ca,Ti,and Mg exceeded 81.18％,67.62％,58.87％,82.15％,and 59.53％,respectively. The XRD patterns indicated that Al and Si in the mullite phase (Al6Si2O13) were chlorinated during the carbochlorination process,resulting in the formation of mullite mesophases (Al4.75Si1.25O9.63 and Al1.83Si1.08O4.85). After the carbochlorination process,Al was accumulated as AlCl3 in the condenser,while SiCl4 and TiCl4 were enriched in the exhaust gas,and CaCl2,MgCl2,and unreacted oxides remained in the residue for further recycling.
万方数据
