Experimental Study Of Additives On The Properties Of Carbon Anode

Carbon anode, as a core component of aluminum electrolytic cell, its performance has direct influence to electrolytic cell’s normal production and various technical economic indexes. In view of the poor performance and high carbon consumption of carbon anode in the air/CO2 antioxidant reaction in China, adding appropriate additives to improve its reactivity is a feasible way, and the key problem is to find the suitable additives. In this paper, we selected nickel carbonate and titanium dioxide as the additive of carbon anode, studied influence principle of additives on the carbon anode reaction; the micro-structure impact of additives on carbon anode and pitch coke; and process impact of additives on asphalt pyrolysis, moreover, we analyze the feasibility of Ti additive on carbon anode to acquire aluminium-titanium alloy,it can broaden the selection thoughts and scope. Research results are as follows:(1)We measured residual anode rate and the pulverization rate of carbon anode with different percentage of Ni additives in air and CO2 atmosphere; measured the carbon anode and asphalt coke by XRD; and monitored the process of asphalt pyrolysis and carbonization by TG-DTG. The result implicated that: the nickel carbonate has significant affect on carbon anode, even the percentage of Ni additives slightly increased, bulk density can be also improved, the pulverization rate and the residual rate of carbon anode in air and CO2 atmosphere can be improved; Ni’s participant also raises apparent activation energy to 52.964KJ/mol during the pyrolyzation process, while pitch’s coke producing rate increases a lot.(2)Observing the carbon anode with different percentage Ti additive, the pulverization rate and residual rate of carbon anode can be enhanced significa ntly in air and CO2 atmosphere; when the percentage of Ti additive is 1.5%, the residual rate of CO2 can be sharply increased by 17.92%; under the same conditions, while the rate in air atmosphere from 51.87% Ti additive free to 68.39%, the micro-grain size of carbon anode is refined; and the Ea of asphalt py rolys is process with additive can reach to 56.405KJ/mol, coking rate is 50.5%.(3) With the process of electrolysis, the electrolytic voltage of carbon with Ti additive is increased tendency.The bottom part of carbon anode with Ti will be consumed to shape of circular arc, and there is electrolytic stuck to it, electrolytic goes into the surface part of carbon anode. After using carbon anode with Ti and prepared Al-Ti alloy. There is phenomenon of segregation for Ti while areas abundant with Ti gets into a shape of stick and there are residual of Al2O3 in the Al electrolytic.The result shows that it’s accessible to electrolyze Al-Ti alloy using carbon anode contained Ti.