Determination of coke, pitch and pores/cracks in green anode by image analysis

Carbon anodes are an essential part of the primary aluminum production. They are made of coal tar pitch, calcined petroleum coke, recycled anodes and butts. As pitch acts as a binder for the anode, its proper distribution in a green anode has a great impact on the properties of the baked anode. Information on cracks in anodes is important for the quality of the baked anode. There is presently no reliable method available to analyze and quantify the amount of coke, pitch and pores/cracks in a green anode sample. In this article, an image analysis technique has been described, that can analyze as well as quantify the area percentage of pores/cracks and weight percentages of pitch and coke. The novelty of the method is its capacity to differentiate the different components of anode