Effect of coke properties and its blending recipe on performances of carbon anode for aluminium electrolysis

Abstract

The properties and blending recipe of petroleum cokes used to make high quality carbon anodes for aluminium electrolysis were studied. Three kinds of green cokes were selected for bench scale study to illustrate the effects of cokes properties and its blending recipe on anode performances. The results show that impurities derived mainly from cokes remarkably affect the CO₂ reactivity and air reactivity of carbon anodes. Ca, Na and V can increase CO₂ reactivity of calcined cokes but S has the contrary effect, and the cokes of high V level generally present high air reactivity. The anodes with good quality can be made by properly selecting and scientifically blending of cokes, some poor quality cokes can also be used to produce high quality anodes with a reasonable blending recipe. Na contaminated anodes have high CO₂ reactivity and air reactivity, so the recycled anode butts should be well cleaned to reduce Na content before being introduced into anode production, which is especially important to the low S cokes.

Keywords

petroleum coke / blending recipe / quality / carbon anode / aluminium electrolysis