摘要
The carbothermal reduction-chlorination-disproportionation of alumina in vacuum was investigated by XRD and thermodynamic analysis. The experiments on alumina and graphite at 1643-1843 K in vacuum were carried out. The results demonstrate that AlCl3（g） reacts with Al2O（g） or Al（g） generated from the carbothermal reduction of alumina to form AlCl（g）, and the AlCl（g） disproportionates to aluminum and AlCl3（g） at a lower temperature and the reaction rate of AlCl（g） reaches 90% at 980 K and 100 Pa. The aluminum can absorb CO to catalyze its disproportionation to C and CO2, and react backward with CO to form Al4C3, Al2O3, C and CO2, resulting in the aluminum product containing C, Al4C3 and Al2O3. The impurities in the aluminum product decrease as the AlCl（g） disproportionation temperature decreases. AlCl3 condenses at a temperature approximated to the room temperature.
通过XRD物相分析和热力学分析研究氧化铝的真空碳热还原—氯化—歧化反应。以氧化铝和石墨为原料,在真空下、1643-1843K的温度范围内进行实验。结果表明,AlCl3(g)与氧化铝碳热还原产生的Al2O(g)或Al(g)反应生成AlCl(g),该AlCl(g)在较低温度下歧化分解为金属铝和AlCl3(g);当压力为100Pa、温度为980K时,AlCl(g)的歧化反应率达到90%。生成的金属铝可以吸附催化CO歧化为C和CO2,并可以与CO二次反应形成Al4C3、Al2O3、C和CO2,导致铝产物中含有C、Al4C3和Al2O3。产物铝中所含的这些杂质随着AlCl(g)歧化反应温度的降低而减少。AlCl3(g)在接近室温的温度下冷凝下来。
基金
Project (u0837604) supported by the Joint Funds of the National Natural Science Foundation of China and Yunnan Province
