Extraction of aluminum by pressure acid-leaching method from coal fly ash
(1. Qinghai Institute of Salt Lake, Chinese Academic of Sciences, Xining 810008, China;
2. The Graduate University of Chinese Academy of Sciences, Beijing 100049, China;
3. Department of Civil Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)
2. The Graduate University of Chinese Academy of Sciences, Beijing 100049, China;
3. Department of Civil Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China)
Abstract: Aluminum was leached out from coal fly ash by pressure acid-leaching method. The effects of coal fly ash size, sulfuric acid concentration, reaction time and reaction temperature on extraction efficiency of aluminum were investigated comprehensively. The phase and morphology of coal fly ash and solid residues after reaction were analyzed by XRD, SEM and IR. The optimal technological conditions for extracting aluminum from coal fly ash were eventually confirmed that coal fly ash with size of 74 μm and sulfuric acid with concentration of 50% are mixed in pressure reaction kettle to react for 4 h at 180 °C. Under the optimal conditions, the extraction efficiency of aluminum can reach 82.4%.
Key words: coal fly ash; aluminum; pressure acid-leaching; extraction efficiency