铝电解中氧化铝溶解过程及结壳行为

利用邱氏高温透明槽实验平台的高速温度采集模块结合原位重量分析法研究了冶金级氧化铝在冰晶石电解质中的溶解过程，尤其是结壳的形成与溶解过程，测定了结壳的溶解速率并分析了结壳的主要物理化学性质.通过对氧化铝溶解结壳过程的热量计算，分析了氧化铝加料过程中的热量平衡，以及加料量、氧化铝预热温度、电解液温度、过热度对溶解过程的影响.研究发现，在热平衡重新建立的过程中，氧化铝从体系中吸收的热量，首先由电解液降温来快速补充；当电解质大幅降温仍满足不了氧化铝的热量需求时，便由电解质冷凝放热来提供热量.相对于较高的电解温度、过热度而言，少量、多频次的氧化铝加料能够获得更加稳定的电解条件.

Dissolution and Agglomeration Behavior of Alumina in Aluminum Electrolysis

The agglomerating behavior and heat transfer process upon the addition of smelting grade alumina into cryolite electrolyte were studied using the see-through cell platform， especially the formation and dissolution of the agglomerate. The dissolution rate of the alumina agglomerate was measured， and physicochemical properties of the alumina agglomerate was analyzed. The influence factors， such as the electrolyte temperature， alumina feeding amount， alumina preheating temperature and superheat during the dissolution and formation of the agglomerate were investigated through heat balance calculation. The results show that during the re-establishment of a new heat balance after alumina feeding， the absorbed heat for alumina dissolution is firstly supplied by electrolyte cooling. When the temperature drop is above the liquidus temperature of the electrolyte， which cannot provide enough heat for the dissolution， electrolyte condensation would take place and release more heat. In contrast to a relatively high electrolyte temperature and high superheat， a high frequent and small amount of alumina feeding would benefit the electrolysis process.