冰晶石熔盐介质中铝热还原月壤模拟样钛铁矿

Aluminothermic Reduction of lunar soil simulant Ilmenite in Cryolite Molten Salt Media

摘要:

以月球资源原位利用为目的,在冰晶石熔盐介质中研究铝热还原钛铁矿制备铝钛铁合金。热力学计算表明,在960℃,铝热还原钛铁矿的相关反应在热力学上可以自发进行。在组成为47.14mass%NaF-42.86mass%AlF₃-10mass%?TiO₃的960℃冰晶石介质中进行铝热还原,研究还原剂用量和还原时间对合金产物的影响。还原产物经XRF、XRD、SEM和EDS分析结果表明,合金产物中有Al、Ti、Fe和少量Si,产物的主要物相是Al₃Ti。随着铝用量的增加,合金产物中Ti的含量逐渐减少,而铁的含量逐渐增加；随着反应时间的延长,产物中Al₃Ti的含量增加。在冰晶石熔盐体系中进行铝热还原2h、还原剂用量为理论用量3倍时,铝中钛含量最高可达18.82mass%。低还原剂用量和较长还原时间时,在冰晶石熔盐介质中还原钛铁矿,可实现Ti/Fe分离；还原反应为原子态的铝还原溶解为离子态的Ti₄₊得到Al-Ti合金。

Abstract:

Focused on in-situ utilization of lunar resources, we studied the preparation of aluminum alloy by aluminothermic reduction of ilmenite in molten cryolite media. The standard Gibbs free energy change of aluminothermic reduction of ilmenite are negative at temperature range 0-1500℃. The effects of reductant amount and reaction time on the aluminothermic reduction of ilmenite in 47.14mass%NaF-42.86mass%AlF₃-10mass%?TiO₃ at 960℃ were studied. The results obtained by XRF, XRD, SEM and EDS analysis show that the products mainly contain Al, Ti, Fe, and little Si, and the main phase of the product is Al₃Ti. With the increase of reductant amount, the content of Ti in alloy products decreases, while the content of Fe in alloy products increases. In addition, the content of Al₃Ti increases with the increase of reaction time. The highest content of Ti in the alloy obtained by aluminothermic reaction for 2h at 960℃ using three times reductant amount of theoretical amount is up to 18.82 mass%. Fe and Ti can be separated when FeTiO₃ aluminothermic reduction was carried using lower reductant amount and higher reduction time. The FeTiO₃ aluminothermic reduction reaction takes place between the dissolved Al atom and dissolved FeTiO₃ in the Cryolite melt.