Influence Of Ball Milled Powder On The Properties Of Carbon Anode Used In Aluminum Electrolysis

The quality of carbon anode will directly affect the quality and the economic benefits of the aluminum production.Thus it is considered to be one of the most critical technologies of aluminum electrolysis. However, nowadays, the quality of our carbon anode has dropped behind the international advanced level seriously, which restrict our aluminum industry severely.The recipe of carbon anode plays a decisive role in the properties of carbon anode.This paper focused on the influence of fines in anode recipe on the properties of carbon anode. First, it was to optimize and refine the preparation process of lab-scale carbon anode. Then, it studied on the influence trend of ultra fines content on all main properties of carbon anode. Base on the research above, through adjusting and optimizing the current recipe of Z anode plant, the effect of fines purity, total content, and ultra fines content on the properties of carbon anode was studied systematically. All of the main conclusions are as followed:(1)A stable set of preparation process of lab-scale carbon anode was completed successfully. The different kneading methods, mold temperature holding methods, paste temperature, and molding pressure were studied and compared.(2)The Blaine value was used to characterized the fineness and specific surface area of power. And it was found that Blaine value of powder had a high sensitivity on its ultra fins content.(3)The Influence of the ultrafine powders content and Blaine value of powder on the properties of carbon anode was studied. And it was found that once the ultrafine powders content in powder beyond 50%, with the increase of its content, the compressive strength, eletrical conductivity, thermal conductivity and air/CO2 activity of carbon anode would be affected adversely, but the air permeability would be improved.(4)It was found that excess powder purity had some adverse effects on some properties of carbon anode. If the powder purity of Z plant could be reduced to 60～70%, the compressive strength, electrical conductivity, thermal conductivity, thermal expansion and air/CO2 reactivity of its carbon anode would be improved greatly. Moreover, the electrical conductivity of its carbon anode could be improved by decreasing the ultra fines content of its powder raw material.