浸后铝用阳极焙烧热解行为研究

Research on pyrolysis behavior of anode baking after aluminum immersion

采用Coats-Redfern近似的热解动力学分析模型,对浸后阳极进行了热重分析,比较三种升温速度下试样的失重特点。结果表明,浸后阳极失重过程分为三个阶段,降低升温速度可使沥青热解反应提前开始,并提前结束,减少热分解量,降低最大失重速率,提高残炭率。在沥青热解反应第二阶段适当降低升温速度,确保热解反应充分完成,有助于提高浸后焙烧后阳极的增重率以及各项物化性能,而在热解反应的第一阶段(室温~200℃)以及第三阶段(550~750℃)可适当提高升温速度,以减少浸后焙烧周期,减少焙烧能耗。浸渍剂沥青的热解反应属于一级反应,随着升温速度的降低,活化能呈减少趋势,反应更加容易进行,反应更充分。

The thermogravimetric analysis of the immersed anode was carried out using the myopic pyrolysis analysis model of Coats-Redfern,and the characteristics of the samples under three heating rates were compared.The result showed that the anodic weight loss process after leaching can be divided into three stages,and the reduction of the heating rate can make the pyrolysis reaction of asphalt begin and end in advance,reduce the amount of thermal decomposition,reduce the maximum weight loss rate,and increase the carbon residue rate.When the pyrolysis reaction of asphalt is fully completed,it’s helpful to improve the weight gain rate and various physicochemical properties of the anode after leaching,while in the fist stage(room temperature to 200℃)and the third stage(550~750℃)of the pyrolysis reaction,the heating rate can be appropriately increased to reduce the roasting cycle and energy consumption after leaching.The pyrolysis reaction of impregnated asphalt is a first-order reaction.With the decrease of the heating rate,the activation energy decreases,making the reaction easier to be carried out and more sufficient.