论文部分内容阅读
提出了一种从氧化铝中提取原铝的新方法。该方法的原理基于如下化学反应:AlI_3+(3/2)Zn=Al+(3/2)ZnI_2。首先通过氧化铝的碳热氯化反应得到氯化铝(AlCl_3),然后通过氯化铝和碘化钙的交换反应(AlCl_3+CaI_2→AlI_3+CaCl_2)得到碘化铝。在实验室条件下对这些反应进行了研究,同时对一些回收主要化学试剂的反应进行了研究(Cl_2,ZnI_2→Zn,CaCl_2→CaI_2)。采用XRD和SEM对反应产物的相组成及形貌进行分析。采用总自由能最小方法对化学反应平衡进行计算。结果表明,采用非电解方法,可以在没有非常高的温度和可消耗的化学试剂的条件下,从氧化铝中有效地提取铝。与当今采用燃煤发电提供电力的铝电解厂相比,本方法所产生的单位碳消耗和CO_2大气排放可以降低一半以上。
A new method of extracting primary aluminum from alumina was proposed. The principle of this method is based on the following chemical reaction: AlI_3 + (3/2) Zn = Al + (3/2) ZnI_2. Aluminum chloride (AlCl 3) was firstly obtained by carbothermal chlorination of alumina and then aluminum iodide was obtained by the exchange reaction (AlCl 3 + CaI 2 → AlI 3 + CaCl 2) between aluminum chloride and calcium iodide. These reactions were studied under laboratory conditions and the reactions of some of the major chemical reagents were also investigated (Cl 2, ZnI 2 → Zn, CaCl 2 → CaI 2). The phase composition and morphology of the reaction product were analyzed by XRD and SEM. The chemical reaction equilibrium is calculated using the minimum total free energy method. The results show that with the non-electrolytic method it is possible to efficiently extract aluminum from alumina without very high temperatures and consumable chemicals. Compared with the current aluminum electrolysis plants that use coal to generate electricity for power generation, the unit carbon consumption and CO 2 emissions generated by this method can be reduced by more than half.