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基于铝电解槽熔体内氧化铝溶解过程动力学机理,提出了综合的传热传质控制模型,以描述未结块和结块氧化铝颗粒的溶解过程。基于相关商业软件和自定义算法,并结合颗粒收缩核模型,采用合适的差分求解方法,对氧化铝颗粒溶解速率、溶解时间和溶解质量进行计算,探讨若干对流和热条件参数对氧化铝溶解过程的影响。结果表明:降低氧化铝浓度和增大氧化铝扩散速率可以增大未结块颗粒溶解速率,减少未结块颗粒溶解时间;提高电解质过热度和氧化铝预热温度可以增大结块颗粒溶解速率,减少结块颗粒溶解时间。对某300 k A铝电解槽内氧化铝溶解过程进行计算分析,得到的氧化铝溶解质量比例曲线数据与文献结果比较接近;氧化铝溶解过程主要分为两个阶段:未结块颗粒的快速溶解和结块颗粒的缓慢溶解,溶解时间数量级大小分别大约为10和100 s;结块颗粒是影响整个氧化铝溶解过程的最主要因素。
Based on the kinetics of alumina dissolution process in the aluminum reduction cell, an integrated heat and mass transfer control model was proposed to describe the dissolution process of un-agglomerated and agglomerated alumina particles. Based on the relevant commercial software and custom algorithms, combined with the particle shrinkage kernel model, the appropriate differential solution method was used to calculate the dissolution rate, dissolution time and dissolution quality of alumina particles. The effects of several convection and thermal parameters on the dissolution process of alumina Impact. The results show that decreasing the alumina concentration and increasing the alumina diffusion rate can increase the dissolution rate of unagglomerated particles and reduce the dissolution time of unagglomerated particles. Increasing the electrolyte superheat and the preheating temperature of alumina can increase the dissolution rate of agglomerated particles , Reducing caking particle dissolution time. The alumina dissolution process in a 300 kA aluminum reduction cell was calculated and analyzed. The data of mass ratio of alumina dissolution obtained were close to the literature results. The dissolution process of alumina was mainly divided into two stages: rapid dissolution of non-agglomerated particles And slow dissolution of caking particles, the dissolution time is about 10 and 100 s, respectively; agglomeration particles are the most important factors affecting the dissolution of alumina.