Simulation Study Of Alumina Concentration And Electrolyte Temperature Field Under Feeding Process In The Aluminum Reduction Cell

Aluminum reduction cell is the core equipment of industrial aluminum production, and alumina is the main raw material for industrial aluminum production. Alumina concentration distribution directly affects the production efficiency and the operation stability of aluminum reduction cell. At the same time, aluminum reduction cell needs to maintain good thermal balance during operation, which can reduce energy consumption in the process of aluminum electrolysis, and the addition of alumina will destroy the thermal equilibrium of cell.According to the research problems of the current domestic and foreign alumina concentration field and electrolyte temperature field, this paper carried out a 420 kA large prebaked alumina reduction cell as the research object. Through the study of the dynamic distribution of alumina concentration, the best feeding and electrolyte concentration-thermal field, this paper provides technical guidance for cell design and feeding optimization process. The main research contents and results are as follows:(1) According to the distribution of electrolyte flow field and the concentration of alumina in the cell, this paper presents alumina feeding and consumption model, and alumina concentration instantaneous distribution model is set up. The model makes up accurate analysis of alumina concentration in the cell according to the time change. For the first time, the max/min alumina concentration c cmax min/, the max/min velocity v vmax min/, the volume ratiovolr and the area ratioarear are adopted to evaluate the periodic stability of alumina concentration distribution. And compared with the measured data well, this verifies the correctness of the model.(2) In order to improve the aluminum feeding mode, this paper systematically considers the influence of feeding point number and position, the feeding period and batch on the alumina concentration distribution. Through comparative analysis, we choose the best feeding mode. The results show: the more feeding point number, the better of alumina concentration distribution. The adjacent feeding point's distance should be appropriate. The more feed batch number, the alumina concentration distribution is better. Under the conditions permit, the feeding period smaller is better. The whole meets more process, less feeding principle, and whole cell alumina concentration distribution is more uniform, which is beneficial to improve the efficiency of producing aluminum.(3) The cell feeding has a significant impact on the electrolyte thermal field, and this paper is the first to establish the electrolyte transient concentration-thermal field model of the cell. Based on the accurate simulation of alumina concentration distribution, we study the change trend of the electrolyte temperature and heat balance during alumina feeding, to provide guidance for the production stability of the cell.